SI general

Unitsystem name: SI general
Description: The SI unit system, using current or historical definitions of the SI units.
The International System of Units (SI) is established and maintained by the General Conference on Weights and Measures (CGPM). The si_general unit system includes all prefixes defined by SI (including the non-SI binary ones), and all units that have either been part of the SI unit system or categorized as accepted for use with the SI.
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    "title": "SI general",
    "description": "The SI unit system, using current or historical definitions of the SI units.\n\nThe International System of Units (SI) is established and maintained by the General Conference on Weights and Measures (CGPM).\nThe si_general unit system includes all prefixes defined by SI (including the non-SI binary ones), and all units that have either been part of the SI unit system or categorized as accepted for use with the SI.",
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        "label": "si_general_unitsystem",
        "kind": "unitsystem",
        "format": "1.2",
        "version": "1.2.0",
        "name": "si_general"
    },
    "units": {
        "A": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ampere",
            "title": "ampere",
            "symbol": "A",
            "display-symbol": "A",
            "description": "A unit of electric current defined according to the current, or one of the historical, definitions of the SI units.\n\nThe current definition at the 26th CGPM Meeting (2018), resolution 1 is: \"The ampere, symbol A, is the SI unit of electric current. It is defined by taking the fixed numerical value of the elementary charge \\(e\\) to be 1.602176634\u00d710\u207b\u00b9\u2079 when expressed in the unit C, which is equal to A\u22c5s, where the second is defined in terms of \\(\\Delta \\nu_\\textrm{Cs}\\).\"\n\nThe earlier definition from the 41st CIPM meeting (1946), Resolution 2: \"The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2\u00d710\u207b\u2077 MKS unit of force per metre of length.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
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                "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/ampere",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/base/ampere",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/base/ampere"
            ],
            "resources": [
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                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Ampere"
                }
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                "label": "ampere_si_general",
                "kind": "unit",
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                "version": "1.2.0",
                "name": "ampere"
            }
        },
        "angstrom": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/angstrom",
            "title": "\u00e5ngstr\u00f6m",
            "symbol": "angstrom",
            "display-symbol": "\u00c5",
            "description": "A unit of length equal to 10\u207b\u00b9\u2070 meter, using the current, or one of the historical, definitions of the SI units.\n\nThe \u00e5ngstr\u00f6m unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 \u00c5 = 0.1 nm = 10\u207b\u00b9\u2070 m\".\n\nThe \u00e5ngstr\u00f6m unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"temporarily admitted\" for use with the SI units.\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Other non-SI units currently accepted for use with the International System.\"\n- The International System of Units (SI), 8th ed. (2006) changes the categorization to \"Other non-SI units\" and adds as a clarifying footnote \"The \u00e5ngstr\u00f6m is widely used by x-ray crystallographers and structural chemists because all chemical bonds lie in the range 1 to 3 \u00e5ngstr\u00f6ms. However it has no official sanction from the CIPM or the CGPM.\"\n- The \u00e5ngstr\u00f6m is omitted in the International System of Units (SI), 9th Edition (2019).\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/angstrom",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/angstrom"
            ],
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                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Angstrom"
                }
            ],
            "defining-relation": {
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                        "symbol": "m",
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                "base-units-expression": "m",
                "scale": {
                    "exponent": -10
                }
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        "arcmin": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/arcminute",
            "title": "arcminute",
            "symbol": "arcmin",
            "display-symbol": "\u2032",
            "alternate-symbols": [
                "minute of arc",
                "minute of angle",
                "MOA",
                "'"
            ],
            "description": "A unit of plane and phase angle equal to 1/60 of a degree representing 1/21600 of a circle, equal to \u03c0/10800 rad, using the current, or one of the historical, definitions of the SI units.\n\nThis definition uses \"arcminute\" as the unit name to distinguish it from the time unit named minute.\nA footnote in the International System of Units, 9th ed. (2019) note that \"arcsecond is an alternative name for second of plane angle\".\nHowever, \"arcminute\" and \"arcmin\" have so far not been mentioned in any of the editions of the International System of Units.\nThey are defined in the GNU Units 3.15 unit database as 1/60 degree.\n\nThe unit appear under the name minute (with symbol \u2032) in the International System of Units (SI), 1st ed. (1970) defined as \"1\u2032 = (1/60)\u00b0 = (\u03c0/10800) rad\".\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) adds as a footnote: \"ISO 31 recommends that the degree be subdivided decimally rather than using the minute and second.\"\n- The International System of Units (SI), 8th ed. (2006) further adds to that footnote: \"For navigation and surveying, however, the minute has the advantage that one minute of latitude on the surface of the Earth corresponds (approximately) to one nautical mile.\"\n- The International System of Units (SI), 9th ed. (2019) replaces the footnote with: \"For some applications such as in astronomy, small angles are measured in arcseconds (i.e. seconds of plane angle), denoted as or \u2032\u2032, or milliarcseconds, microarcseconds and picoarcseconds, denoted mas, \u03bcas and pas, respectively, where arcsecond is an alternative name for second of plane angle.\"\n  The formulation \"denoted as or \u2033\" is reproduced here faithfully from the source and suggests an alternate symbol may have been omitted due to a typographical error.\n  It is not clear what alternate symbol was intended to be referenced.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
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                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Minute_and_second_of_arc"
                }
            ],
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                        "symbol": "pi",
                        "id": "https://schemas.optimade.org/defs/v1.2/constants/math/basic/pi"
                    },
                    {
                        "symbol": "rad",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/radian"
                    }
                ],
                "base-units-expression": "pi*rad",
                "scale": {
                    "denominator": 10800
                }
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                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "arcminute"
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        },
        "arcsec": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/arcsecond",
            "title": "arcsecond",
            "symbol": "arcsec",
            "display-symbol": "\u2033",
            "alternate-symbols": [
                "second of plane angle",
                "second of arc",
                "\""
            ],
            "description": "A unit of plane and phase angle equal to 1/60 of an arcminute representing 1/1296000 of a circle, equal to \u03c0/648000 rad, using the current, or one of the historical, definitions of the SI units.\n\nThis definition uses \"arcsecond\" as the unit name to distingush it from the time unit named minute.\nThe unit appear under the name second (with symbol \u2033) in the International System of Units (SI), 1st ed. (1970) defined as \"1\u2033 = (1/60)\u2032 = (\u03c0/648 000) rad.\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) adds as a footnote: \"ISO 31 recommends that the degree be subdivided decimally rather than using the minute and second.\"\n- The International System of Units (SI), 8th ed. (2006) further adds to that footnote: \"For navigation and surveying, however, the minute has the advantage that one minute of latitude on the surface of the Earth corresponds (approximately) to one nautical mile.\"\n- The International System of Units (SI), 9th ed. (2019) replaces the footnote with: \"For some applications such as in astronomy, small angles are measured in arcseconds (i.e. seconds of plane angle), denoted as or \u2032\u2032, or milliarcseconds, microarcseconds and picoarcseconds, denoted mas, \u03bcas and pas, respectively, where arcsecond is an alternative name for second of plane angle.\"\n  The formulation \"denoted as or \u2033\" is reproduced here faithfully from the source and suggests an alternate symbol may have been omitted due to a typographical error.\n  It is not clear what alternate symbol was intended to be referenced.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
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                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Minute_and_second_of_arc"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "pi",
                        "id": "https://schemas.optimade.org/defs/v1.2/constants/math/basic/pi"
                    },
                    {
                        "symbol": "rad",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/radian"
                    }
                ],
                "base-units-expression": "pi*rad",
                "scale": {
                    "denominator": 648000
                }
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                "label": "arcsecond_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "arcsecond"
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        },
        "are": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/are",
            "title": "are",
            "symbol": "a",
            "display-symbol": "a",
            "description": "A unit of area equal to 100 square meters (10\u00b2 m\u00b2) using the current, or one of the historical, definitions of the SI units.\n\nThe are unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 a = 1 dam\u00b2 = 10\u00b2 m\u00b2\" with the footnote \"This unit and its symbol were adopted by the International Committee in 1879 (Proces-Verbaux C.I.P.M., 1879, p. 41).\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"units in use temporarily\".\n- The International System of Units (SI), 5th ed. (1985) adds the clarification that the unit is \"used to express agrarian areas.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Other non-SI units currently accepted for use with the International System.\"\n- The International System of Units (SI), 8th ed. (2006) completely removes the unit (but still defines the hectare).\n\nThe are unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
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                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Hectare#Are"
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            ],
            "defining-relation": {
                "base-units": [
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                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    }
                ],
                "base-units-expression": "m^2",
                "scale": {
                    "exponent": 4
                }
            },
            "x-optimade-definition": {
                "label": "are_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "are"
            }
        },
        "au": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/astronomicalunit",
            "title": "astronomical unit",
            "symbol": "au",
            "display-symbol": "au",
            "description": "A unit of length representing the mean distance between the Earth and the Sun, using the current, or one of the historical, definitions given in the editions of the International System of Units (SI).\n\nThe current definition in the International System of Units (SI), 9th ed. (2019) is: \"1 au = 149 597 870 700 m\" with the footnote \"As decided at the XXVIII General Assembly of the International Astronomical Union (Resolution B2, 2012).\"\n\nThe prior definition in the International System of Units (SI), 1st ed. (1970) appears in a footnote: \"The astronomical unit of distance is the length of the unperturbed circular orbit about the Sun of a body of infinitesimal mass in motion around the Sun with an angular sidereal velocity of 0.017202098950 radians per ephemeris day of 86,400 seconds. In the System of Astronomical Constants of the International Astronomical Union, the adopted value is: 1 AU = 149,600 x 10\u2076 m.\"\n\nThis definition interprets the definition to be the expression in radians and seconds, with the meter value regarded only as an approximation.\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units for use with the SI in specific domains.\"\n- The International System of Units (SI), 2nd ed. (1973) categorizes the unit as \"Non-SI units accepted for use with the International System, whose values in SI units are obtained experimentally\" and prefixes the footnote with: \"This unit does not have an international symbol; abbreviations are used, for example, UA in French, AU in English, AG in German, \u0430.\u0435. in Russian, etc.\"\n- The International System of Units (SI), 4th ed. (1981) omits the unit.\n- The International System of Units (SI), 7th ed. (1998) reintroduces the unit in the category \"Non-SI units accepted for use with the International System, whose values in SI units are obtained experimentally.\" with the experimental relationship \"1 au = 1.49597870691(30)\u00d710\u00b9\u00b9 m\" with the footnote: \"The astronomical unit is a unit of length approximatively equal to the mean Earth-Sun distance. Its value is such that, when used to describe the motion of bodies in the Solar System, the heliocentric gravitational constant is (0.01720209895)\u00b2 ua\u00b3\u22c5d\u207b\u00b2.\"\n- The International System of Units (SI), 8th ed. (2006) notes the experimental relationship \"1 au = 1.49597870691(6)\u00d710\u00b9\u00b9 m\" and changes the footnote to: \"The astronomical unit is approximately equal to the mean Earth-Sun distance. It is the radius of an unperturbed circular Newtonian orbit about the Sun of a particle having infinitesimal mass, moving with a mean motion of 0.01720209895 radians per day (known as the Gaussian constant). The value given for the astronomical unit is quoted from the IERS Conventions 2003 (D.D. McCarthy and G. Petit eds., IERS Technical Note 32, Frankfurt am Main: Verlag des Bundesamts f\u00fcr Kartographie und Geod\u00e4sie, 2004, 12). The value of the astronomical unit in metres comes from the JPL ephemerides DE403 (Standish E.M., Report of the IAU WGAS Sub-Group on Numerical Standards, Highlights of Astronomy, Appenzeller ed., Dordrecht: Kluwer Academic Publishers, 1995, 180-184).\"\n- The International System of Units (SI), 9th ed. (2019) categorizes the astronomical unit as a \"non-SI unit accepted for use with the SI units\" and redefines it to have an exact relationship to the meter with the footnote: \"As decided at the XXVIII General Assembly of the International Astronomical Union (Resolution B2, 2012).\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
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                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Astronomical_unit"
                }
            ],
            "$comment": "While the approximate relation given is exact in the current definition of the SI system, this unit definition is a generalized definition that may also reference prior definitions of the astronomical unit, for which this relationship is only approximate.",
            "approximate-relations": [
                {
                    "base-units": [
                        {
                            "symbol": "m",
                            "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                        }
                    ],
                    "base-units-expression": "m",
                    "scale": {
                        "value": 149597870700
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                "kind": "unit",
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                "name": "astronomicalunit"
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        },
        "atm": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/atmosphere",
            "title": "standard atmosphere",
            "symbol": "atm",
            "display-symbol": "atm",
            "description": "A unit for pressure approximately equal to the average atmospheric pressure at sea level on Earth using the current, or one of the historical, definitions of the SI units.\n\nThe standard atmosphere unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 atm = 101325 Pa\" with the footnote \"Resolution 4 at the 10th C.G.P.M. (1954).\"\n(While the pascal unit appears in the 1st ed. as a symbol for N\u00b7s/m\u00b2, it was adopted into SI at the 14th CGPM meeting in 1971.)\n\n- In the International System of Units (SI), 1st ed. (1970) it is categorized as \"temporarily admitted\" for use with the SI units.\n- The International System of Units (SI), 4th ed. (1981) changes the categorization to \"Other units generally deprecated\" and adds to the footnote that: \"The designation \"standard atmosphere\" for a reference pressure of 101 325 Pa is still acceptable.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Examples of other non-SI units.\"\n- The International System of Units (SI), 8th ed. (2006) omits the unit, but uses the term in a footnote to the definition of the unit bar to clarify that prior to 1982 the standard pressure used to tabulate thermodynamical data was the standard atmosphere.\n- The International System of Units (SI), 9th ed. (2006) no longer references the unit or the designation \"standard atmosphere\".\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
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                },
                {
                    "relation": "Definition of pascal at the 14th CGPM Meeting (1971)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/14-1971"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Standard_atmosphere_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "kg*m^-1*s^-2",
                "scale": {
                    "numerator": 101325
                }
            },
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                "label": "atmosphere_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "atmosphere"
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        },
        "u": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/atomicmassunit",
            "title": "atomic mass unit",
            "symbol": "u",
            "display-symbol": "u",
            "alternate-symbols": [
                "dalton",
                "Da"
            ],
            "description": "A unit of mass representing 1/12 of the mass of a free carbon 12 atom (i.e., a typical value of the mass of a nucleon in an atom) using the current, or one of the historical, definitions given in the editions of the International System of Units (SI).\n\nThe International System of Units (SI), 1st ed. (1970) defines the atomic mass unit in the section \"Units used with the International System\" (known as \"Non-SI units accepted for use with the SI units\" in later editions).\nThe unit is defined in a footnote as: \"The atomic mass unit (unified) is equal to 1/12 of the mass of an atom of the nuclide \u00b9\u00b2C; 1 u = 1.66053 x 10\u207b\u00b2\u2077 kg approximately.\"\n\nThe definition is retained in the International System of Units up to the 7th edition (1998), where the conditions are slightly clarified and dalton (Da) is introduced as an alternative name: \"The unified atomic mass unit is equal to 1/12 of the mass of an unbound atom of the nuclide \u00b9\u00b2C, at rest, and in its ground state. In the field of biochemistry, the unified atomic mass unit is also called the dalton, symbol Da.\"\nIn the 8th ed. (2006) the definition is slightly adjusted, replacing \"unbound\" with \"free\": \"The dalton (Da) and the unified atomic mass unit (u) are alternative names (and symbols) for the same unit, equal to 1/12 times the mass of a free carbon 12 atom, at rest and in its ground state.\"\n\nAll editions of the International System of Units note approximate relationships to the kilogram.\nThe 9th ed. states \"1 Da = 1.660 539 066 60(50)\u00d710\u207b\u00b2\u2077 kg\", where the 2018 CODATA value has been used and the 2019 SI kilogram is referenced (https://schemas.optimade.org/defs/v1.2/units/si/2019/base/kilogram).\n\nIn the 2019 redefinition of the SI units, the atomic mass unit is the only unit listed as accepted for use with SI that has a value in SI units which is determined experimentally.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/atomicmassunit",
                "https://schemas.optimade.org/defs/v1.2/units/si/1998/accepted/dalton",
                "https://schemas.optimade.org/defs/v1.2/units/si/general/dalton"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Dalton_(unit)"
                },
                {
                    "relation": "CODATA unified atomic mass unit fundamental physical constant: source for relationship to kg",
                    "resource-id": "https://physics.nist.gov/cgi-bin/cuu/Value?ukg"
                }
            ],
            "approximate-relations": [
                {
                    "base-units": [
                        {
                            "symbol": "kg",
                            "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                        }
                    ],
                    "base-units-expression": "kg",
                    "scale": {
                        "value": 1.6605390666e-27,
                        "standard_uncertainty": 5e-37
                    }
                }
            ],
            "x-optimade-definition": {
                "label": "atomicmassunit_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "atomicmassunit"
            }
        },
        "b": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/barn",
            "title": "barn",
            "symbol": "b",
            "display-symbol": "b",
            "description": "A unit of area used in nuclear physics to express cross sections equal to 100 fm\u00b2 using the current, or one of the historical, definitions of the SI units.\n\nThe International System of Units (SI), 1st ed. (1970) states: \"1 b = 100 fm\u00b2 = 10\u207b\u00b2\u2078 m\" with a footnote \"The barn is a special unit used in nuclear physics to express cross sections.\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use temporarily with the International System.\"\n- The International System of Units (SI), 8th ed. (2006) categorizes the unit as \"Other non-SI units currently accepted for use with the International System.\"\n- The International System of Units (SI), 9th ed. (2019) categorizes the unit as \"Other non-SI units.\"\n\nThe barn unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/barn",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/barn"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Barn_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    }
                ],
                "scale": {
                    "exponent": 4
                },
                "base-units-expression": "m^2"
            },
            "x-optimade-definition": {
                "label": "barn_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "barn"
            }
        },
        "bar": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/bar",
            "title": "bar",
            "symbol": "bar",
            "display-symbol": "bar",
            "description": "A unit of pressure equal to 10\u2075 N/m using the current, or one of the historical, definitions of the SI units.\n\nThe bar unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 bar = 0,1 MPa = 10\u2075 Pa\" with the footnote \"This unit and its symbol are included in Resolution 7 of the 9th C.G.P.M. (1948).\"\n(While the pascal unit appears in the 1st ed. as a symbol for N\u00b7s/m\u00b2, it was adopted into SI at the 14th CGPM meeting in 1971.)\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use temporarily with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Other non-SI units currently accepted for use with the International System.\"\n- The International System of Units (SI), 8th ed. (2006) changes the categorization to \"Other non-SI units\" and updates the footnote to: \"The bar and its symbol are included in Resolution 7 of the 9th CGPM (1948; CR, 70). Since 1982 one bar has been used as the standard pressure for tabulating all thermodynamic data. Prior to 1982 the standard pressure used to be the standard atmosphere, equal to 1.013 25 bar, or 101 325 Pa.\"\n- The bar is omitted in the International System of Units (SI), 9th Edition (2019) (except appearing as an example in the context of typesetting of units).\n\nThe bar unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/bar",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/bar"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Bar_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "kg*m^-1*s^-2",
                "scale": {
                    "exponent": 5
                }
            },
            "x-optimade-definition": {
                "label": "bar_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "bar"
            }
        },
        "Bq": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/becquerel",
            "title": "becquerel",
            "symbol": "Bq",
            "display-symbol": "Bq",
            "description": "A unit for radioactivity, defined as s\u207b\u00b9 using the current, or one of the historical, definitions of the SI units.\n\n\"The 15th Conf\u00e9rence G\u00e9n\u00e9rale des Poids et Mesures, [...] adopts the following special name for the SI unit of activity: becquerel, symbol Bq, equal to one reciprocal second.\" [15th CGPM Meeting (1975)]\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1975/named/becquerel"
            ],
            "resources": [
                {
                    "relation": "Definition at the 15th CGPM Meeting (1975)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/15-1975"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Becquerel"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "s^-1"
            },
            "x-optimade-definition": {
                "label": "becquerel_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "becquerel"
            }
        },
        "cd": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/candela",
            "title": "candela",
            "symbol": "cd",
            "display-symbol": "cd",
            "description": "A unit of luminous intensity in a given direction defined according to the current, or one of the historical, definitions of the SI units.\n\nThe current definition in its most recent phrasing at the 26th CGPM Meeting in 2018, resolution 1 is: \"The candela, symbol cd, is the SI unit of luminous intensity in a given direction. It is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540\u00d710\u00b9\u00b2 Hz, \\(K_\\mathrm{cd}\\), to be 683 when expressed in the unit lm\u22c5W\u207b\u00b9, which is equal to cd\u22c5sr\u22c5W\u207b\u00b9, or cd\u22c5sr\u22c5kg\u207b\u00b9\u22c5m\u207b\u00b2\u22c5s\u00b3, where the kilogram, metre and second are defined in terms of \\(h\\), \\(c\\) and \\(\\Delta \\nu_\\textrm{Cs}\\).\"\n\nThis is a rephrasing of a definition at the 16th CGPM Meeting (1979), resolution 3: \"The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540\u00d710\u00b9\u00b2 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.\"\n\nEarlier different definitions of the candela were:\n\n- \"The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540\u00d710\u00b9\u00b2 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.\" [16th CGPM Meeting (1979), resolution 3].\n- \"The candela is the sixtieth of the luminous intensity emitted perpendicularly by one square centimeter of a perfect radiator (black body) at the solidification temperature of platinum.\" [9th CGPM meeting (1948)] (this definition was adopted into the SI system at the 11th CGPM Meeting in 1960, resolution 12).\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/candela",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/candela",
                "https://schemas.optimade.org/defs/v1.2/units/si/1979/base/candela",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/base/candela",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/base/candela"
            ],
            "resources": [
                {
                    "relation": "Definition in the 26th CGPM Meeting in 2018, resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Candela"
                }
            ],
            "x-optimade-definition": {
                "label": "candela_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "candela"
            }
        },
        "C": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/coulomb",
            "title": "coulomb",
            "symbol": "C",
            "display-symbol": "C",
            "description": "A unit for electric charge equal to s\u00b7A using the current, or one of the historical, definitions of the SI units.\n\n\"The coulomb is the amount of electricity transported in one second by a current of one ampere.\" [9th CGPM meeting in 1946]\n\nThe coulomb was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12, implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1; the metre at the 17th CGPM meeting (1983), resolution 1; and the kilogram at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/coulomb",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/coulomb",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/coulomb",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/coulomb"
            ],
            "resources": [
                {
                    "relation": "Definition at the 9th CGPM meeting (1948)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
                },
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram in the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Coulomb"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    },
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ampere"
                    }
                ],
                "base-units-expression": "A*s"
            },
            "x-optimade-definition": {
                "label": "coulomb_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "coulomb"
            }
        },
        "Ci": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/curie",
            "title": "curie",
            "symbol": "Ci",
            "display-symbol": "Ci",
            "description": "A unit of activity with the value 3.7\u00b710\u207b\u00b9\u2070 s\u207b\u00b9 using the current, or one of the historical, definitions of the SI units.\n\nDefined as outside the SI at the 12th CGPM meeting in 1964, resolution 7.\nImplicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use temporarily with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Other non-SI units\".\n- The curie is omitted in the International System of Units (SI), 8th Edition (2006).\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1964/temporary/curie",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/temporary/curie"
            ],
            "resources": [
                {
                    "relation": "Definition at the 12th CGPM meeting (1964), resolution 3",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/12-1964/resolution-3"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Le Syst\u00e8me International d'Unit\u00e9s (SI) (1970)",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Curie_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "s^-1",
                "scale": {
                    "numerator": 37,
                    "exponent": -11
                }
            },
            "x-optimade-definition": {
                "label": "curie_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "curie"
            }
        },
        "da": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/dalton",
            "title": "dalton",
            "symbol": "Da",
            "display-symbol": "Da",
            "alternate-symbols": [
                "u"
            ],
            "description": "A unit of mass intended to represent a typical mass of a nucleon in an atom using the current, or one of the historical, definitions given in the editions of the International System of Units (SI).\n\nThe name dalton as an alternative name to *atomic mass unit* is defined in the International System of Units (SI), 7th ed. (1998) in a footnote to a table labeled \"Non-SI units accepted for use with the International System, whose values in SI units are obtained experimentally\" in the section \"Units outside the international system\".\nThe definition given is: \"The unified atomic mass unit is equal to 1/12 of the mass of an unbound atom of the nuclide \u00b9\u00b2C, at rest, and in its ground state. In the field of biochemistry, the unified atomic mass unit is also called the dalton, symbol Da.\"\n\nThis definition makes the dalton equivalent to the atomic mass unit defined in the International System of Units (SI), 1st ed. (1970) (https://schemas.optimade.org/defs/v1.2/units/si/general/atomicmassunit)\n\nIn the International System of Units (SI) 8th ed. (2006) the definition is slightly adjusted, replacing \"unbound\" with \"free\": \"The dalton (Da) and the unified atomic mass unit (u) are alternative names (and symbols) for the same unit, equal to 1/12 times the mass of a free carbon 12 atom, at rest and in its ground state.\"\n\nAll editions of the International System of Units (SI) note approximate relationships to the kilogram.\nThe 9th ed. states \"1 Da = 1.660 539 066 60(50)\u00d710\u207b\u00b2\u2077 kg\", where the 2018 CODATA value has been used and the 2019 SI kilogram is referenced (https://schemas.optimade.org/defs/v1.2/units/si/2019/base/kilogram).\n\nNote: in the 2019 redefinition of the SI units, the dalton is the only unit listed as accepted for use with SI that does not have an exact relation to the base SI units.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/general/atomicmassunit"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Dalton_(unit)"
                },
                {
                    "relation": "CODATA unified atomic mass unit fundamental physical constant: source for relationship to kg",
                    "resource-id": "https://physics.nist.gov/cgi-bin/cuu/Value?ukg"
                }
            ],
            "approximate-relations": [
                {
                    "base-units": [
                        {
                            "symbol": "kg",
                            "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                        }
                    ],
                    "base-units-expression": "kg",
                    "scale": {
                        "value": 1.6605390666e-27,
                        "standard_uncertainty": 5e-37
                    }
                }
            ],
            "x-optimade-definition": {
                "label": "dalton_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "dalton"
            }
        },
        "day": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/day",
            "title": "day",
            "symbol": "day",
            "display-symbol": "day",
            "alternate-symbols": [
                "d"
            ],
            "description": "A unit of time equal to 86 400 seconds using the current, or one of the historical, definitions of the SI units.\n\nThe day unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 d = 24 h = 86400 s\".\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Non-SI units accepted for use with the International System.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/day"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Day"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "s",
                "scale": {
                    "numerator": 86400
                }
            },
            "x-optimade-definition": {
                "label": "day_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "day"
            }
        },
        "degC": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/degcelsius",
            "title": "degree Celsius",
            "symbol": "degC",
            "display-symbol": "\u00b0C",
            "alternate-symbols": [
                "degreecelsius"
            ],
            "description": "A unit of temperature, defined as kelvin offset with +273.15 using the current, or one of the historical, definitions of the SI units.\n\n\"If we add to the practical international Celsius temperatures defined above T\u2080 = 273.15 degrees, we obtain the practical international Kelvin temperatures. By subtracting T\u2080 from the thermodynamic temperatures, we obtain the thermodynamic Celsius temperatures.\" [11th CGPM meeting (1960)]\n\nThe degree Celsius was defined and included in SI at the 11th CGPM meeting in 1960, resolution 12 and implicitly redefined via the redefinitions of the kelvin at the 13th CGPM Meeting in 1967, resolution 4 and at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/degcelsius",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/degcelsius",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/degcelsius"
            ],
            "resources": [
                {
                    "relation": "Definition at the 11th CGPM meeting (1960)",
                    "resource-id": "https://www.bipm.og/en/committees/cg/cgpm/11-1960"
                },
                {
                    "relation": "Redefinition of the kelvin at the 13th CGPM meeting (1967), resolution 4",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-4"
                },
                {
                    "relation": "Redefinition of the kelvin at the 26th CGPM meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Celsius"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "K",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kelvin"
                    }
                ],
                "base-units-expression": "K",
                "offset": {
                    "numerator": 27315,
                    "denominator": 100
                }
            },
            "x-optimade-definition": {
                "label": "degcelsius_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "degcelsius"
            }
        },
        "deg": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/degree",
            "title": "degree",
            "symbol": "degree",
            "display-symbol": "\u00b0",
            "description": "A unit of plane and phase angle representing 1/360 of a full circle, equal to \u03c0/180 rad using the current, or one of the historical, definitions of the SI units.\n\nWith the current definition of raidan in the SI system, the degree is equal to 1/360 of a circle.\n\nThe degree unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1\u00b0 = (pi/180) rad\".\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) adds as a footnote: \"ISO 31 recommends that the degree be subdivided decimally rather than using the minute and second.\"\n- The International System of Units (SI), 8th ed. (2006) further adds to that footnote: \"For navigation and surveying, however, the minute has the advantage that one minute of latitude on the surface of the Earth corresponds (approximately) to one nautical mile.\"\n- The International System of Units (SI), 9th ed. (2019) replaces the footnote with: \"For some applications such as in astronomy, small angles are measured in arcseconds (i.e. seconds of plane angle), denoted as or \u2032\u2032, or milliarcseconds, microarcseconds and picoarcseconds, denoted mas, \u03bcas and pas, respectively, where arcsecond is an alternative name for second of plane angle.\"\n  The formulation \"denoted as or \u2033\" is reproduced here faithfully from the source and suggests an alternate symbol may have been omitted due to a typographical error.\n  It is not clear what alternate symbol was intended to be referenced.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/degree"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Degree_(angle)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "pi",
                        "id": "https://schemas.optimade.org/defs/v1.2/constants/math/basic/pi"
                    },
                    {
                        "symbol": "rad",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/radian"
                    }
                ],
                "base-units-expression": "pi*rad",
                "scale": {
                    "denominator": 180
                }
            },
            "x-optimade-definition": {
                "label": "degree_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "degree"
            }
        },
        "eV": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/electronvolt",
            "title": "electron volt",
            "symbol": "eV",
            "display-symbol": "eV",
            "description": "A unit of energy that representing the kinetic energy acquired by an electron as it accelerates through a 1 volt potential difference in a vacuum using the current, or one of the historical, definitions given in the editions of the International System of Units (SI).\n\nThe electronvolt unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 electronvolt is the energy acquired by an electron after traversing a potential difference of 1 V in a vacuum; 1 eV = 1.60219\u00d710\u207b\u00b9\u2079 J approximately.\"\nThis definition makes the unit equal to 1 volt times the value of the elementary charge.\nIn the 2019 redefinition of the SI units the elementary charge is exactly 1.602176634\u00b710\u207b\u00b9\u2079 C, making the electron volt exactly equal to 1.602176634\u00b710\u207b\u00b9\u2079 J.\nThe International System of Units (SI), 9th ed. (2019) accordingly notes the exact relationship with the SI 2019 derived unit joule as \"1 eV = 1.602176634\u00b710\u207b\u00b9\u2079 J\" but retains the definition from 1970 in a footnote.\n\nThe unit is categorized in the International System of Units (SI), 9th ed. (2019) as \"Non-SI units accepted for use with the SI units\".\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/electronvolt",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/accepted/electronvolt",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/accepted/electronvolt"
            ],
            "resources": [
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                    "relation": "Definition in the International System of Units (SI), 9th Edition",
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                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Electronvolt"
                }
            ],
            "approximate-relations": [
                {
                    "base-units": [
                        {
                            "symbol": "V",
                            "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/volt"
                        },
                        {
                            "symbol": "e",
                            "id": "https://schemas.optimade.org/defs/v1.2/constants/codata/2018/electromagnetic/elementarycharge"
                        }
                    ],
                    "base-units-expression": "e*V"
                }
            ],
            "x-optimade-definition": {
                "label": "electronvolt_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "electronvolt"
            }
        },
        "F": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/farad",
            "title": "farad",
            "symbol": "F",
            "display-symbol": "F",
            "description": "A unit for electrical capacitance equal to kg\u207b\u00b9\u00b7m\u207b\u00b2\u00b7s\u2074\u00b7A\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The farad is the capacitance of an electric capacitor between whose plates an electric potential difference of one volt appears when it is charged with an amount of electricity equal to one coulomb.\" [9th CGPM meeting in 1946]\n\nThe farad was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12 and implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1, and the redefinitions of the ampere and kilogram at the 26th CGPM Meeting in 2018, resolution 1\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/farad",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/farad",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/farad",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/farad"
            ],
            "resources": [
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram and ampere in the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Farad"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "A^2*kg^-1*m^-2*s^4"
            },
            "x-optimade-definition": {
                "label": "farad_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "farad"
            }
        },
        "Gal": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/gal",
            "title": "gal",
            "symbol": "Gal",
            "display-symbol": "Gal",
            "description": "A unit of acceleration equal to 1 centimeter per second squared (1 cm/s\u00b2), using the current, or one of the historical, definitions of the SI units.\n\nThe gal unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 Gal = 1 cm/s\u00b2 = 10\u207b\u00b2 m/s\u00b2\" with the footnote \"The gal is a special unit of acceleration employed in geodesy and geophysics to express acceleration due to gravity.\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"units in use temporarily\".\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"derived CGS units with special names\".\n- The International System of Units (SI), 9th ed. (2019) moves the unit definition to the margin aside the table for Non-SI units accepted for use with the SI units.\n  It is not clear how to interpret the categorization intended with this placement of the unit.\n\nThe galileo unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/gal",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/gal"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Gal_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "m*s^-2",
                "scale": {
                    "exponent": -2
                }
            },
            "x-optimade-definition": {
                "label": "gal_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "gal"
            }
        },
        "Gy": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/gray",
            "title": "gray",
            "symbol": "Gy",
            "display-symbol": "Gy",
            "description": "A unit for absorbed dose of ionizing radiation equal to m\u00b2\u00b7s\u207b\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The 15th Conf\u00e9rence G\u00e9n\u00e9rale des Poids et Mesures, [...] adopts the following special name for the SI unit of ionizing radiation: gray, symbol Gy, equal to one joule per kilogram.\" [15th CGPM Meeting (1975)]\n\nThe gray was defined at the 15th CGPM Meeting in 1975, and implicitly redefined via the redefinition of the meter at the 17th CGPM Meeting in 1983, resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1975/named/gray",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/gray"
            ],
            "resources": [
                {
                    "relation": "Definition at the 15th CGPM Meeting (1975)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/15-1975"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Gray_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "m^2*s^-2"
            },
            "x-optimade-definition": {
                "label": "gray_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "gray"
            }
        },
        "ha": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/hectare",
            "title": "hectare",
            "symbol": "ha",
            "display-symbol": "ha",
            "description": "A unit of area equal to 1000 square meters (1 hm\u00b2), using the current, or one of the historical, definitions of the SI units.\n\nThe hectare unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 ha = 1 hm\u00b2 = 10\u2074 m\u00b2\" with the footnote \"This unit and its symbol were adopted by the International Committee in 1879 (Proces-Verbaux C.I.P.M., 1879, p. 41).\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"units in use temporarily\".\n- The International System of Units (SI), 5th ed. (1985) add the clarification that the unit is \"used to express agrarian areas.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Other non-SI units currently accepted for use with the International System.\"\n\nThe hectare unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/hectare",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/hectare"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Hectare"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    }
                ],
                "base-units-expression": "m^2",
                "scale": {
                    "exponent": 4
                }
            },
            "x-optimade-definition": {
                "label": "hectare_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "hectare"
            }
        },
        "H": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/henry",
            "title": "henry",
            "symbol": "H",
            "display-symbol": "H",
            "description": "A unit for inductance equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b2\u00b7A\u207b\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The henry is the inductance of a closed circuit in which an electromotive force of one volt is produced when the electric current passing through the circuit varies uniformly at a rate of one ampere per second.\" [9th CGPM meeting in 1946]\n\nThe henry was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12, and implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1, the metre at the 17th CGPM meeting (1983), resolution 1, and the kilogram and ampere at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/henry",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/henry",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/henry",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/henry"
            ],
            "resources": [
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the second at the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram and ampere at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Henry_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "A^-2*kg*m^2*s^-2"
            },
            "x-optimade-definition": {
                "label": "henry_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "henry"
            }
        },
        "Hz": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/hertz",
            "title": "hertz",
            "symbol": "Hz",
            "display-symbol": "Hz",
            "description": "A unit for frequency equal to s\u207b\u00b9 using the current, or one of the historical, definitions of the SI units.\n\n\"The frequency of a periodic phenomenon is expressed in hertz, as the inverse of its period expressed in seconds.\" [9th CGPM meeting in 1946]\n\nThe hertz was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/hertz",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/hertz"
            ],
            "resources": [
                {
                    "relation": "Definition at the 9th CGPM meeting (1948)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
                },
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Hertz"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "s^-1"
            },
            "x-optimade-definition": {
                "label": "hertz_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "hertz"
            }
        },
        "h": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/hour",
            "title": "hour",
            "symbol": "h",
            "display-symbol": "h",
            "description": "A unit of time equal to 60 minutes, or 3600 seconds, using the current, or one of the historical, definitions of the SI units.\n\nThe hour unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 h = 60 min = 3600 s\".\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Non-SI units accepted for use with the International System.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/hour"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Hour"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "s",
                "scale": {
                    "numerator": 3600
                }
            },
            "x-optimade-definition": {
                "label": "hour_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "hour"
            }
        },
        "J": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/joule",
            "title": "joule",
            "symbol": "J",
            "display-symbol": "J",
            "description": "A derived SI unit for energy, work, and heat equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The joule is the work produced by a newton whose point of application moves one meter in the direction of the force.\" [9th CGPM meeting in 1946]\n\nThe joule was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12, implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1, the metre at the 17th CGPM meeting (1983), resolution 1, and the kilogram at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/joule",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/joule",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/joule",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/joule"
            ],
            "resources": [
                {
                    "relation": "Definition at the 9th CGPM meeting (1948)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
                },
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Joule"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "kg*m^2*s^-2"
            },
            "x-optimade-definition": {
                "label": "joule_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "joule"
            }
        },
        "kat": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/katal",
            "title": "katal",
            "symbol": "kat",
            "display-symbol": "kat",
            "description": "A derived SI unit for catalytic activity, defined as mol\u00b7s\u207b\u00b9 using the current, or one of the historical, definitions of the SI units.\n\n\"The 21st Conf\u00e9rence G\u00e9n\u00e9rale des Poids et Mesures, [...] decides to adopt the special name katal, symbol kat, for the SI unit mole per second to express catalytic activity, especially in the fields of medicine and biochemistry, and recommends that when the katal is used, the measurand be specified by reference to the measurement procedure; the measurement procedure must identify the indicator reaction.\" [21st CGPM meeting (1999), resolution 12]\n\nThe katal unit was implicitly redefined via the redefinition of the mole at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1999/named/katal",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/katal"
            ],
            "resources": [
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Katal"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "mol",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/mole"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "mol*s^-1"
            },
            "x-optimade-definition": {
                "label": "katal_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "katal"
            }
        },
        "K": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kelvin",
            "title": "kelvin",
            "symbol": "K",
            "display-symbol": "K",
            "description": "A unit of thermodynamic temperature using the current, or one of the historical, definitions of the SI units.\n\nThe current definition at the 26th CGPM Meeting in 2018, resolution 1 is: \"The kelvin, symbol K, is the SI unit of thermodynamic temperature. It is defined by taking the fixed numerical value of the Boltzmann constant k to be 1.380649\u00d710\u207b\u00b2\u00b3 when expressed in the unit J\u22c5K\u207b\u00b9, which is equal to kg\u22c5m\u00b2\u22c5s\u207b\u00b2\u22c5K\u207b\u00b9, where the kilogram, metre and second are defined in terms of \\(h\\), \\(c\\) and \\(\\Delta \\nu_\\textrm{Cs}\\).\" [26th CGPM Meeting (2018), resolution 1].\n\nThe prior definition at the 13th CGPM Meeting in 1967, resolution 4, was: \"The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water.\"\nThis definition changed the symbol and rephrased the definition of the unit \"degree Kelvin\" from the 10th CGPM meeting in 1954: \"The 10th Conf\u00e9rence G\u00e9n\u00e9rale des Poids et Mesures decides to define the thermodynamic temperature scale by choosing the triple point of water as the fundamental fixed point, and assigning to it the temperature 273.16 degrees Kelvin, exactly.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/kelvin",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/base/kelvin",
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/degreekelvin"
            ],
            "resources": [
                {
                    "relation": "Definition in the 26th CGPM Meeting in 2018, resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Kelvin"
                }
            ],
            "x-optimade-definition": {
                "label": "kelvin_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "kelvin"
            }
        },
        "kg": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram",
            "title": "kilogram",
            "symbol": "kg",
            "display-symbol": "kg",
            "description": "A unit of mass using the current, or one of the historical, definitions of the SI units.\n\nThe current definition at the 26th CGPM Meeting in 2018, resolution 1 is: \"The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant \\(h\\) to be 6.62607015\u00d710\u207b\u00b3\u2074 when expressed in the unit J\u22c5s, which is equal to kg\u22c5m\u00b2\u22c5s\u207b\u00b9, where the metre and the second are defined in terms of \\(c\\) and \\(\\Delta \\nu_\\textrm{Cs}\\).\"\n\nThe prior definition at the 1st CGPM Meeting (1889) was: \"The prototype of the kilogram adopted by the International Committee; This prototype will henceforth be considered as the unit of mass;\", referring to the international prototype of the kilogram made of platinum-iridium.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/base/kilogram"
            ],
            "resources": [
                {
                    "relation": "Definition in the 26th CGPM Meeting in 2018, resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Kilogram"
                }
            ],
            "x-optimade-definition": {
                "label": "kilogram_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "kilogram"
            }
        },
        "knot": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/knot",
            "title": "knot",
            "symbol": "knot",
            "display-symbol": "knot",
            "description": "A unit of speed primarily used in navigation defined as 1 nautical mile per hour which is equal to (1852/3600) m/s using the current, or one of the historical, definitions of the SI units.\n\nThe knot unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 nautical mile per hour = (1852/3600) m/s.\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use temporarily with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Other non-SI units currently accepted for use with the International System.\"\n- The International System of Units (SI), 8th ed. (2006) changes the categorization to \"Other non-SI units.\"\n- The knot is omitted in the International System of Units (SI), 9th Edition (2019).\n\nThe knot unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/knot",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/knot"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Knot_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "ms^-1",
                "scale": {
                    "numerator": 1852,
                    "denominator": 3600
                }
            },
            "x-optimade-definition": {
                "label": "knot_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "knot"
            }
        },
        "l": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/litre",
            "title": "litre",
            "symbol": "l",
            "display-symbol": "l",
            "alternate-symbols": [
                "L",
                "liter"
            ],
            "description": "The litre, or liter is a unit of volume equal to a cubic decimetre (1 dm\u00b3) using the current, or one of the historical, definitions of the SI units.\n\n\"The 12th Conf\u00e9rence G\u00e9n\u00e9rale des Poids et Mesures (CGPM) [...] declares that the word 'litre' may be employed as a special name for the cubic decimetre\" [12th CGPM meeting (1964), resolution 6].\n\nThe litre was defined at the 12th CGPM meeting in 1964, resolution 6, and implicitly redefined with the redefinition of the metre at the 17th CGPM Meeting in 1983, resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1964/accepted/litre",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/accepted/litre"
            ],
            "resources": [
                {
                    "relation": "Definition at the 12th CGPM meeting (1964), resolution 6",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/12-1964/resolution-6"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Litre"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    }
                ],
                "base-units-expression": "m^3",
                "scale": {
                    "exponent": -3
                }
            },
            "x-optimade-definition": {
                "label": "litre_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "litre"
            }
        },
        "lm": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/lumen",
            "title": "lumen",
            "symbol": "lm",
            "display-symbol": "lm",
            "description": "A derived SI unit for luminous flux equal to cd\u00b7sr using the current, or one of the historical, definitions of the SI units.\n\n\"The lumen is the luminous flux emitted in a steradian by a uniform point source with a luminous intensity of one candela.\" [9th CGPM meeting in 1946]\n\nThe lumen was defined at the 9th CGPM meeting in 1946, implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1, the candela at the 16th CGPM Meeting in 1979, resolution 3, the metre at the 17th CGPM Meeting in 1983, resolution 1, and the candela (implicitly redefined via the kilogram) at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/lumen",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/lumen",
                "https://schemas.optimade.org/defs/v1.2/units/si/1979/named/lumen",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/lumen",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/lumen"
            ],
            "resources": [
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the candela at the 16th CGPM Meeting in 1979, resolution 3.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/16-1979/resolution-3"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting in 1967, resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting in 1983, resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Lumen_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "cd",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/candela"
                    },
                    {
                        "symbol": "sr",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/steradian"
                    }
                ],
                "base-units-expression": "cd*sr"
            },
            "x-optimade-definition": {
                "label": "lumen_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "lumen"
            }
        },
        "lx": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/lux",
            "title": "lux",
            "symbol": "lx",
            "display-symbol": "lx",
            "description": "A derived SI unit for illuminance equal to cd\u22c5sr\u22c5m\u207b\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The lux is the illuminance of a surface that receives a uniformly distributed luminous flux of one lumen per square meter.\" [9th CGPM meeting in 1946]\n\nThe lux was defined at the 9th CGPM meeting in 1946, and implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1, the candela at the 16th CGPM Meeting in 1979, resolution 3, the metre at the 17th CGPM meeting (1983), resolution 1, and the candela (implicitly redefined via the kilogram) at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/lux",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/lux",
                "https://schemas.optimade.org/defs/v1.2/units/si/1979/named/lux",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/lux",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/lux"
            ],
            "resources": [
                {
                    "relation": "Definition at the 9th CGPM meeting (1948)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
                },
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the candela at the 16th CGPM Meeting in 1979, resolution 3.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/16-1979/resolution-3"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Lux"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "cd",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/candela"
                    },
                    {
                        "symbol": "sr",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/steradian"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    }
                ],
                "base-units-expression": "cd*m^-2*sr"
            },
            "x-optimade-definition": {
                "label": "lux_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "lux"
            }
        },
        "m": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre",
            "title": "metre",
            "symbol": "m",
            "display-symbol": "m",
            "alternate-symbols": [
                "metre",
                "meter"
            ],
            "description": "The metre, or meter, is a unit of length using the current, or one of the historical, definitions of the SI units.\n\nThe current definition in its most recent phrasing at the 26th CGPM Meeting in 2018, resolution 1 is: \"The metre, symbol m, is the SI unit of length. It is defined by taking the fixed numerical value of the speed of light in vacuum \\(c\\) to be 299792458 when expressed in the unit m\u22c5s\u207b\u00b9, where the second is defined in terms of the caesium frequency \\(\\Delta \\nu_\\textrm{Cs}\\).\"\n\nThis is a rephrasing of a definition at the 17th CGPM Meeting (1983), resolution 1: \"The metre is the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second.\" [17th CGPM Meeting (1983), resolution 1].\n\nThe prior definition at the 11th CGPM meeting (1960), resolution 6 was: \"The metre is the length equal to 1650763.73 wavelengths in vacuum of the radiation corresponding to the transition between the levels 2p\u2081\u2080 and 5d\u2085 of the krypton 86 atom.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/base/metre"
            ],
            "resources": [
                {
                    "relation": "Definition at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Definition at the 11th CGPM meeting (1960), resolution 6.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-6"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Metre"
                }
            ],
            "x-optimade-definition": {
                "label": "metre_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "metre"
            }
        },
        "min": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/minute",
            "title": "minute",
            "symbol": "min",
            "display-symbol": "min",
            "description": "A unit of time that is equal to 60 seconds, using the current, or one of the historical, definitions of the SI units.\n\nThe minute unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 min = 60 s\".\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Non-SI units accepted for use with the International System.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/minute"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Minute"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
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                ],
                "base-units-expression": "s",
                "scale": {
                    "numerator": 60
                }
            },
            "x-optimade-definition": {
                "label": "minute_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "minute"
            }
        },
        "mol": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/mole",
            "title": "mole",
            "symbol": "mol",
            "display-symbol": "mol",
            "description": "A unit of amount of substance using the current, or one of the historical, definitions of the SI units.\n\nThe current definition at the 26th CGPM Meeting in 2018, resolution 1 is: \"The mole, symbol mol, is the SI unit of amount of substance. One mole contains exactly 6.02214076\u00d710\u00b2\u00b3 elementary entities. This number is the fixed numerical value of the Avogadro constant, \\(N_A\\), when expressed in the unit mol\u207b\u00b9 and is called the Avogadro number. The amount of substance, symbol \\(n\\), of a system is a measure of the number of specified elementary entities. An elementary entity may be an atom, a molecule, an ion, an electron, any other particle or specified group of particles.\"\n\nThe prior definition at the 14th CGPM Meeting (1971), resolution 3 was: \"1. The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilogram of carbon 12. 2. When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles.\" This definition was clarified at the 69th CIPM meeting in 1980 by appending: \"In this definition, it is understood that unbound atoms of carbon 12, at rest and in their ground state, are referred to.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1971/base/mole",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/base/mole"
            ],
            "resources": [
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                    "relation": "Definition in the 26th CGPM Meeting in 2018, resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Definition in the 14th CGPM Meeting in 1971, resolution 3",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/14-1971/resolution-3"
                },
                {
                    "relation": "Clarification in the 96th meeting of the CIPM",
                    "resource-id": "https://www.bipm.org/en/committees/ci/cipm/69-1980"
                },
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Mole_(unit)"
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            ],
            "x-optimade-definition": {
                "label": "mole_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "mole"
            }
        },
        "nauticalmile": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/nauticalmile",
            "title": "nautical mile",
            "symbol": "M",
            "display-symbol": "M",
            "alternate-symbols": [
                "NM",
                "Nm",
                "nmi"
            ],
            "description": "A unit of length primarily used in navigation defined as 1852 m using the current, or one of the historical, definitions of the SI units.\n\nThe nautical mile unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 nautical mile = 1852 m\" with the footnote \"The nautical mile is a special unit employed for marine and aerial navigation to express distance. The conventional value given above was adopted by the First International Extraordinary Hydrographic Conference, Monaco, 1929, under the name 'International nautical mile'.\"\nHistorically, the nautical mile was defined as the meridian arc length corresponding to one arcminute of latitude.\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use temporarily with the International System.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Other non-SI units currently accepted for use with the International System\" and adds to the footnote that: \"As yet there is no internationally agreed symbol. This unit was originally chosen because one nautical mile on the surface of the Earth subtends approximately one minute of angle at the centre.\"\n- The International System of Units (SI), 8th ed. (2006) changes the categorization to \"Other non-SI units\" and adjusts the footnote to say: \"As yet there is no internationally agreed symbol, but the symbols M, NM, Nm, and nmi are all used; in the table the symbol M is used. The unit was originally chosen, and continues to be used, because one nautical mile on the surface of the Earth subtends approximately one minute of angle at the centre of the Earth, which is convenient when latitude and longitude are measured in degrees and minutes of angle.\"\n- The nautical mile is omitted in the International System of Units (SI), 9th Edition (2019).\n\nThe nautical mile unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/nauticalmile",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/nauticalmile"
            ],
            "resources": [
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                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Nautical_mile"
                }
            ],
            "defining-relation": {
                "base-units": [
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                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
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                ],
                "base-units-expression": "m",
                "scale": {
                    "numerator": 1852
                }
            },
            "x-optimade-definition": {
                "label": "nauticalmile_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "nauticalmile"
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        },
        "N": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/newton",
            "title": "newton",
            "symbol": "N",
            "display-symbol": "N",
            "description": "A unit for force and weight equal to kg\u00b7m\u00b7s\u207b\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The newton is the force that, in one second, imparts to a mass equal to one kilogram an increase in speed of one meter per second.\" [9th CGPM meeting in 1946]\n\nThe newton was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12, implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1, the metre at the 17th CGPM meeting (1983), resolution 1, and the kilogram at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/newton",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/newton",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/newton",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/newton"
            ],
            "resources": [
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Newton_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "kg*m*s^-2"
            },
            "x-optimade-definition": {
                "label": "newton_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "newton"
            }
        },
        "ohm": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ohm",
            "title": "ohm",
            "symbol": "ohm",
            "display-symbol": "\u03a9",
            "description": "A unit for electrical resistance equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b3\u00b7A\u207b\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The ohm is the electrical resistance that exists between two points of a conductor when a constant potential difference of one volt, applied between these two points, produces a current of one ampere in the conductor, provided that the conductor is not the seat of any electromotive force.\" [9th CGPM meeting in 1946]\n\nThe ohm was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12, implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1, the metre at the 17th CGPM meeting (1983), resolution 1, and the kilogram and ampere at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/ohm",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/ohm",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/ohm",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/ohm"
            ],
            "resources": [
                {
                    "relation": "Definition at the 9th CGPM meeting (1948)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
                },
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram and the ampere at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Ohm"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "A^-2*kg*m^2*s^-3"
            },
            "x-optimade-definition": {
                "label": "ohm_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "ohm"
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        },
        "pc": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/parsec",
            "title": "parsec",
            "symbol": "pc",
            "display-symbol": "pc",
            "description": "A unit of length representing the distance at which 1 astronomical unit subtends an angle of 1 arcsecond using the current, or one of the historical, definitions of the SI units.\n\nThe parsec unit appears in the International System of Units (SI), 1st ed. (1970) defined in a footnote as \"1 parsec is the distance at which 1 astronomical unit subtends an angle of 1 arcsecond; therefore, approximately, 1 pc = 206 265 AU = 30 857 x 10\u00b9\u00b2 m.\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units for use with the SI in specific domains.\"\n- The International System of Units (SI), 2nd ed. (1973) categorizes the unit as \"Non-SI units accepted for use with the International System, whose values in SI units are obtained experimentally.\"\n- The International System of Units (SI), 4th ed. (1981) and later editions omit the unit.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/parsec"
            ],
            "resources": [
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                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Parsec"
                }
            ],
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                    "base-units": [
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                            "symbol": "m",
                            "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                        }
                    ],
                    "scale": {
                        "value": 3.0857e+16
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                }
            ],
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                "label": "parsec_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "parsec"
            }
        },
        "Pa": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/pascal",
            "title": "pascal",
            "symbol": "Pa",
            "display-symbol": "Pa",
            "description": "A unit for pressure and stress equal to kg\u00b7m\u207b\u00b9\u00b7s\u207b\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The International Committee will ask the General Conference to approve two special names: pascal (symbol Pa) for the SI unit of pressure (N/m\u00b2), [...]\" [14th CGPM Meeting (1971)].\n\nThe pascal was defined at the 14th CGPM Meeting in 1971 and implicitly redefined via the redefinitions of the metre at the 17th CGPM Meeting in 1983, resolution 1, and the kilogram at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1971/named/pascal",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/pascal",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/pascal"
            ],
            "resources": [
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                    "relation": "Definition at the 14th CGPM Meeting (1971)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/14-1971"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Pascal_(unit)"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "kg*m^-1*s^-2"
            },
            "x-optimade-definition": {
                "label": "pascal_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "pascal"
            }
        },
        "rad": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/radian",
            "title": "radian",
            "symbol": "rad",
            "display-symbol": "rad",
            "alternate-symbols": [
                "radian"
            ],
            "description": "A unit of plane angle representing the relation of the arc length on a circle intercepted at a given radius so that the full circle has an angle of 4\u03c0 radians using the current, or one of the historical, definitions of the SI units.\n\nThe radian is defined at the 9th CGPM Meeting in 1948 as: \"The radian is the angle with its vertex at the center of a circle that intercepts an arc of length equal to the radius on the circumference of that circle.\"\n\nThe International System of Units (SI), 9th ed. (2019) has a longer but equivalent definition: \"The plane angle, expressed in radian, between two lines originating from a common point is the length of circular arc \\(s\\), swept out between the lines by a radius vector of length \\(r\\) from the common point divided by the length of the radius vector, \\(\\theta\\) = \\(s/r\\) rad. The phase angle (often just referred to as the \u201cphase\u201d) is the argument of any complex number. It is the angle between the positive real axis and the radius of the polar representation of the complex number in the complex plane. One radian corresponds to the angle for which \\(s = r\\), thus 1 rad = 1. The measure of the right angle is exactly equal to the number \u03c0/2.\"\n\nThe radian is categorized in the International System of Units (SI), 1st Edition as a supplementary SI unit.\nAt the 20th CGPM meeting in 1995, resolution 8 the categorization was changed to a dimensionless derived SI unit.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/supplementary/radian"
            ],
            "resources": [
                {
                    "relation": "Definition at the 9th CGPM meeting (1948)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
                },
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Reclassification at the 20th CGPM meeting (1995)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/20-1995/resolution-8"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Radian"
                }
            ],
            "x-optimade-definition": {
                "label": "radian_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "radian"
            }
        },
        "radiationunit": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/radiationunit",
            "title": "radiation unit",
            "symbol": "radiationunit",
            "display-symbol": "rad",
            "description": "A unit used to express the absorbed dose of ionizing radiation defined as 10\u207b\u00b2 J/kg using the current, or one of the historical, definitions of the SI units.\n\nThis unit definition uses \"radiationunit\" as the symbol for this unit despite \"rad\" being in common use, to distinguish it from the radian, which is an SI unit with rad as its symbol.\n\nThe radiation unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 rad = 10\u207b\u00b2 J/kg\" with the footnote: \"The rad is a special unit employed to express absorbed dose of ionizing radiation. When there is risk of confusion with the symbol for radian, rd may be used as the symbol for rad.\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use temporarily with the International System.\"\n- The International System of Units (SI), 3rd ed. (1977) changes the definition to use the unit gray: \"1 rad = cGy = 10\u207b\u00b2 Gy.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Examples of other non-SI units\" and adds the additional footnote: \"Note that this non-SI unit is exactly equivalent to an SI unit with an appropriate submultiple prefix.\"\n- The International System of Units (SI), 8th ed. (2006) omits the unit.\n\nThe roentgen unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/radiationunit",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/radiationunit"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Rad_(radiation_unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "J",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/joule"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    }
                ],
                "base-units-expression": "J*kg^-1",
                "scale": {
                    "exponent": -2
                }
            },
            "x-optimade-definition": {
                "label": "radiationunit_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "radiationunit"
            }
        },
        "rem": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/rem",
            "title": "roentgen equivalent man",
            "symbol": "rem",
            "display-symbol": "rem",
            "description": "The \"roentgen equivalent man\" (rem) is a unit used in radioprotection meant to represent a dose of any ionizing radiation comparable in effect to one roentgen of high-voltage x-radiation, taken to be equal to 10\u207b\u00b2 Sv using the current, or one of the historical, definitions of the SI units.\n\nThe rem unit appears in the International System of Units (SI), 4th ed. (1981) defined as \"1 rem = 1 cSv = 10\u207b\u00b2 Sv\" with the footnote: \"The rem is a special unit used in radioprotection to express the equivalent dose.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1981/temporary/rem"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 4th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Roentgen_equivalent_man"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "kg*m^2*s^-2",
                "scale": {
                    "exponent": -2
                }
            },
            "x-optimade-definition": {
                "label": "rem_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "rem"
            }
        },
        "R": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/roentgen",
            "title": "roentgen",
            "symbol": "R",
            "display-symbol": "R",
            "description": "A unit used to express the exposure of ionizing radiation defined as 2.58 x 10\u207b\u2074 C/kg using the current, or one of the historical, definitions of the SI units.\n\nThe roentgen unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 R = 2.58 x 10\u207b\u2074 C/kg\" with the footnote: \"The roentgen is a special unit used to express the ionization exposure of ionizing radiation.\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use temporarily with the International System.\"\n- The International System of Units (SI), 2nd ed. (1973) rephrases the footnote to: \"The roentgen is a special unit used to express the exposure of X or gamma radiation.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Examples of other non-SI units\".\n- The International System of Units (SI), 8th ed. (2006) omits the unit.\n\nThe roentgen unit was implicitly redefined via the redefinition of the metre at the 17th CGPM meeting (1983), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/roentgen",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/roentgen"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 1st Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Roentgen_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "C",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/coulomb"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    }
                ],
                "base-units-expression": "C*kg^-1",
                "scale": {
                    "numerator": 258,
                    "exponent": -6
                }
            },
            "x-optimade-definition": {
                "label": "roentgen_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "roentgen"
            }
        },
        "s": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second",
            "title": "second",
            "symbol": "s",
            "display-symbol": "s",
            "description": "A unit of time using the current, or one of the historical, definitions of the SI units.\n\nThe current definition in its most recent phrasing at the 26th CGPM Meeting in 2018, resolution 1 is: \"The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency, \\(\\Delta \\nu_\\textrm{Cs}\\), the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9192631770 when expressed in the unit Hz, which is equal to s\u207b\u00b9.\"\n\nThis is a rephrasing of a definition at the 13th CGPM Meeting (1967), resolution 1: \"The second is the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom.\"\n\nThe earlier definition at the 11th CGPM Meeting in 1960, resolution 9 was: \"The second is the fraction 1/31556925.9747 of the tropical year for 1900 January 0 at 12 hours ephemeris time.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/second",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
            ],
            "resources": [
                {
                    "relation": "Definition in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Rephrased definition in the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Definition at the 11th CGPM meeting (1960), resolution 6.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-6"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Second"
                }
            ],
            "x-optimade-definition": {
                "label": "second_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "second"
            }
        },
        "S": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/siemens",
            "title": "siemens",
            "symbol": "S",
            "display-symbol": "S",
            "description": "A unit for electrical conductance equal to kg\u207b\u00b9\u00b7m\u207b\u00b2\u00b7s\u00b3\u00b7A\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The International Committee will ask the General Conference to approve two special names: [...] siemens (symbol S) for the SI unit of conductance (\u03a9\u207b\u00b9).\" [14th CGPM Meeting (1971)].\n\nThe siemens was defined at the 14th CGPM Meeting in 1971 and implicitly redefined via the redefinitions of the meter at the 17th CGPM Meeting in 1983, resolution 1 and the kilogram at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1971/named/siemens",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/siemens",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/siemens"
            ],
            "resources": [
                {
                    "relation": "Definition at the 14th CGPM Meeting (1971)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/14-1971"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Siemens_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "A^2*kg^-1*m^-2*s^3"
            },
            "x-optimade-definition": {
                "label": "siemens_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "siemens"
            }
        },
        "Sv": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/sievert",
            "title": "sievert",
            "symbol": "Sv",
            "display-symbol": "Sv",
            "description": "A unit for equivalent dose of ionizing radiation equal to m\u00b2\u00b7s\u207b\u00b2 using the current, or one of the historical, definitions of the SI units.\n\n\"The 16th Conf\u00e9rence G\u00e9n\u00e9rale des Poids et Mesures, [...] adopts the special name sievert, symbol Sv, for the SI unit of dose equivalent in the field of radioprotection. The sievert is equal to the joule per kilogram.\" [16th CGPM meeting (1979), resolution 5]\n\nThe sievert was defined at the 16th CGPM meeting in 1979 and implicitly redefined via the redefinition of the meter at the 17th CGPM Meeting in 1983, resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1979/named/sievert",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/sievert"
            ],
            "resources": [
                {
                    "relation": "Definition at the 16th CGPM meeting (1979), resolution 5",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/16-1979/resolution-5"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Sievert"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "m^2*s^-2"
            },
            "x-optimade-definition": {
                "label": "sievert_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "sievert"
            }
        },
        "sr": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/steradian",
            "title": "steradian",
            "symbol": "sr",
            "display-symbol": "sr",
            "alternate-symbols": [
                "sterad"
            ],
            "description": "A unit of solid angle representing the relation of the area cut out on a sphere at a given radius so that the entire sphere has a solid angle of 4\u03c0 steradians using the current, or one of the historical, definitions of the SI units.\n\nThe radian is defined at the 9th CGPM Meeting in 1948 as: \"The unit of solid angle is the steradian. The steradian is the solid angle with its vertex at the center of a sphere with a radius of one meter, which cuts out an area of one square meter on the surface of that sphere.\"\n\nThe International System of Units (SI), 9th Edition give a rephrased but equivalent definition: \"The solid angle, expressed in steradian, corresponds to the ratio between an area \\(A\\) of the surface of a sphere of radius \\(r\\) and the squared radius, \\(\\Omega = A/r^2\\) sr. One steradian corresponds to the solid angle for which \\(A = r^2\\), thus 1 sr = 1.\"\n\nThe steradian is categorized in the International System of Units (SI), 1st Edition as a supplementary SI unit.\nAt the 20th CGPM meeting in 1995, resolution 8 the categorization was changed to a dimensionless derived SI unit.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/supplementary/steradian"
            ],
            "resources": [
                {
                    "relation": "Definition at the 9th CGPM meeting (1948)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
                },
                {
                    "relation": "Establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Reclassification at the 20th CGPM meeting (1995)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/20-1995/resolution-8"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Steradian"
                }
            ],
            "x-optimade-definition": {
                "label": "steradian_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "steradian"
            }
        },
        "T": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/tesla",
            "title": "tesla",
            "symbol": "T",
            "display-symbol": "T",
            "description": "A unit for magnetic flux density equal to kg\u00b7s\u207b\u00b2\u00b7A\u207b\u00b9 using the current, or one of the historical, definitions of the SI units.\n\nThe tesla was defined as 1 Wb/m in the introduction of the SI unit system the 11th CGPM Meeting in 1960, resolution 12, implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1, the ampere (implicitly via the redefinition of the metre) at the 17th CGPM Meeting in 1983, resolution 1, and the kilogram and ampere at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/tesla",
                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/tesla",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/tesla",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/tesla"
            ],
            "resources": [
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram and the ampere at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Tesla_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "A^-1*kg*s^-2"
            },
            "x-optimade-definition": {
                "label": "tesla_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "tesla"
            }
        },
        "t": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/tonne",
            "title": "tonne",
            "symbol": "t",
            "display-symbol": "t",
            "alternate-symbols": [
                "t"
            ],
            "description": "A unit of mass equal to 1000 kg using the current, or one of the historical, definitions of the SI units.\n\nThe International System of Units (SI), 1st ed. (1970) defines the tonne as \"1 t = 10\u00b3 kg\" with the footnote \"The symbol and the unit was defined in resolution 7 at the 9th meeting of the C.G.P.M. (1948).\"\n\nIn the 2019 implicit redefinition of the tonne, the kilogram in the definition refers to the 2019 kilogram SI base unit (https://schema.optimade.org/units/si/2019/named/kilogram).\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units used with the International System\"\n- The International System of Units (SI), 3rd ed. (19) changes the reference of the definition to the 1879 meeting of the CIPM page 41.\n- The International System of Units (SI), 6th ed. (1991) further adds \"In some English-speaking countries this unit is called \u226ametric ton\u226b.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/tonne",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/accepted/tonne"
            ],
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Tonne"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    }
                ],
                "base-units-expression": "kg",
                "scale": {
                    "exponent": 3
                }
            },
            "x-optimade-definition": {
                "label": "tonne_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "tonne"
            }
        },
        "V": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/volt",
            "title": "volt",
            "symbol": "V",
            "display-symbol": "V",
            "description": "A unit for electric potential, voltage, and electromotive force equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b3\u00b7A\u207b\u00b9 using the current, or one of the historical, definitions of the SI units.\n\n\"The volt is the electric potential difference that exists between two points of a conducting wire carrying a constant current of one ampere when the power dissipated between these points is equal to one watt.\" [9th CGPM meeting in 1946]\n\nThe volt was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12 and implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1, the metre at the 17th CGPM Meeting in 1983, resolution 1, and the kilogram at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
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                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/volt",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/volt"
            ],
            "resources": [
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the kilogram at the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Volt"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    },
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ampere"
                    }
                ],
                "base-units-expression": "A^-1*kg*m^2*s^-3"
            },
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                "label": "volt_si_general",
                "kind": "unit",
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                "version": "1.2.0",
                "name": "volt"
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        },
        "W": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/watt",
            "title": "watt",
            "symbol": "W",
            "display-symbol": "W",
            "description": "A unit for power and radiant flux equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b3 using the current, or one of the historical, definitions of the SI units.\n\n\"The watt is the power that produces one joule per second.\" [9th CGPM meeting in 1946]\n\nThe watt was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12, implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1; the metre at the 17th CGPM meeting (1983), resolution 1; and the kilogram at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
            "compatibility": [
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                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/watt",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/watt",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/watt"
            ],
            "resources": [
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
                },
                {
                    "relation": "Redefinition of the metre at the 17th CGPM meeting (1983), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/17-1983/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Watt"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "kg*m^2*s^-3"
            },
            "x-optimade-definition": {
                "label": "watt_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "watt"
            }
        },
        "Wb": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/weber",
            "title": "weber",
            "symbol": "Wb",
            "display-symbol": "Wb",
            "description": "A unit for magnetic flux equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b3\u00b7A\u207b\u00b9 using the current, or one of the historical, definitions of the SI units.\n\n\"The weber is the magnetic induction flux that, passing through a single-turn circuit, produces an electromotive force of one volt if it is reduced to zero in one second by uniform decay.\" [9th CGPM meeting in 1946]\n\nThe weber was defined at the 9th CGPM Meeting in 1946, included in SI at the 11th CGPM meeting in 1960, resolution 12, implicitly redefined via the redefinitions of the second at the 13th CGPM Meeting in 1967, resolution 1; the metre at the 17th CGPM meeting (1983), resolution 1; and the kilogram at the 26th CGPM Meeting (2018), resolution 1.\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
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                "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/weber",
                "https://schemas.optimade.org/defs/v1.2/units/si/1983/named/weber",
                "https://schemas.optimade.org/defs/v1.2/units/si/2019/named/weber"
            ],
            "resources": [
                {
                    "relation": "Definition at the 9th CGPM meeting (1948)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
                },
                {
                    "relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Redefinition of the kilogram in the 26th CGPM Meeting (2018), resolution 1",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Weber_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second"
                    }
                ],
                "base-units-expression": "A^-1*kg*m^2*s^-3"
            },
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                "label": "weber_si_general",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "weber"
            }
        }
    },
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            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/yotta",
            "title": "yotta",
            "symbol": "Y",
            "display-symbol": "Y",
            "description": "The yotta SI prefix defined as a dimensionless multiple of 10\u00b2\u2074, defined at the 19th CGPM Meeting in 1991, resolution 4.",
            "resources": [
                {
                    "relation": "Definition in the 19th CGPM Meeting in 1991, resolution 4",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/19-1991/resolution-4"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 24
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            },
            "x-optimade-definition": {
                "label": "yotta_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "yotta"
            }
        },
        "Z": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/zetta",
            "title": "zetta",
            "symbol": "Z",
            "display-symbol": "Z",
            "description": "The zetta SI prefix defined as a dimensionless multiple of 10\u00b2\u00b9, defined at the 19th CGPM Meeting in 1991, resolution 4.",
            "resources": [
                {
                    "relation": "Definition in the 19th CGPM Meeting in 1991, resolution 4",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/19-1991/resolution-4"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 21
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            },
            "x-optimade-definition": {
                "label": "zetta_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "zetta"
            }
        },
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            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/exa",
            "title": "exa",
            "symbol": "E",
            "display-symbol": "E",
            "description": "The exa SI prefix defined as a dimensionless multiple of 10\u00b9\u2078, defined at the 15th CGPM Meeting in 1975, resolution 10.",
            "resources": [
                {
                    "relation": "Definition in the 15th CGPM Meeting in 1975, resolution 10",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/15-1975/resolution-10"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
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                "base-units-expression": "",
                "scale": {
                    "exponent": 18
                }
            },
            "x-optimade-definition": {
                "label": "exa_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "exa"
            }
        },
        "P": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/peta",
            "title": "peta",
            "symbol": "P",
            "display-symbol": "P",
            "description": "The peta SI prefix defined as a dimensionless multiple of 10\u00b9\u2075, defined at the 15th CGPM Meeting in 1975, resolution 10.",
            "resources": [
                {
                    "relation": "Definition in the 15th CGPM Meeting in 1975, resolution 10",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/15-1975/resolution-10"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
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            "defining-relation": {
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                "base-units-expression": "",
                "scale": {
                    "exponent": 15
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                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "peta"
            }
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            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/tera",
            "title": "tera",
            "symbol": "T",
            "display-symbol": "T",
            "description": "The tera SI prefix defined as a dimensionless multiple of 10\u00b9\u00b2, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
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                "base-units-expression": "",
                "scale": {
                    "exponent": 12
                }
            },
            "x-optimade-definition": {
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                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "tera"
            }
        },
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            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/giga",
            "title": "giga",
            "symbol": "G",
            "display-symbol": "G",
            "description": "The giga SI prefix defined as a dimensionless multiple of 10\u2079, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Giga-"
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            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 9
                }
            },
            "x-optimade-definition": {
                "label": "giga_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "giga"
            }
        },
        "M": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/mega",
            "title": "mega",
            "symbol": "M",
            "display-symbol": "M",
            "description": "The mega SI prefix defined as a dimensionless multiple of 10\u2076, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Mega-"
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                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 6
                }
            },
            "x-optimade-definition": {
                "label": "mega_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "mega"
            }
        },
        "k": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/kilo",
            "title": "kilo",
            "symbol": "k",
            "display-symbol": "k",
            "description": "The kilo SI prefix defined as a dimensionless multiple of 10\u00b3, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Kilo-"
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                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 3
                }
            },
            "x-optimade-definition": {
                "label": "kilo_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "kilo"
            }
        },
        "h": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/hecto",
            "title": "hecto",
            "symbol": "h",
            "display-symbol": "h",
            "description": "The hecto SI prefix defined as a dimensionless multiple of 10\u00b2, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Hecto-"
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            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 2
                }
            },
            "x-optimade-definition": {
                "label": "hecto_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "hecto"
            }
        },
        "da": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/deca",
            "title": "deca",
            "symbol": "da",
            "display-symbol": "da",
            "description": "The deca SI prefix defined as a dimensionless multiple of 10, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Deca-"
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                    "exponent": 1
                }
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                "label": "deca_prefix_si",
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                "format": "1.2",
                "version": "1.2.0",
                "name": "deca"
            }
        },
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            "symbol": "d",
            "display-symbol": "d",
            "description": "The deci SI prefix defined as a dimensionless multiple of 10\u207b\u00b9, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
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                    "relation": "Wikipedia article describing the prefix",
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                    "exponent": -1
                }
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                "format": "1.2",
                "version": "1.2.0",
                "name": "deci"
            }
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            "symbol": "c",
            "display-symbol": "c",
            "description": "The centi SI prefix defined as a dimensionless multiple of 10\u207b\u00b2, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
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                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
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                "scale": {
                    "exponent": -2
                }
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                "label": "centi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "centi"
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        },
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            "title": "milli",
            "symbol": "m",
            "display-symbol": "m",
            "description": "The milli SI prefix defined as a dimensionless multiple of 10\u207b\u00b3, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Milli-"
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            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -3
                }
            },
            "x-optimade-definition": {
                "label": "milli_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "milli"
            }
        },
        "mc": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/micro",
            "title": "micro",
            "symbol": "mc",
            "display-symbol": "\u03bc",
            "description": "The micro SI prefix defined as a dimensionless multiple of 10\u207b\u2076, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.\n\nThe micro SI prefix is the only one not using a Latin symbol.\nBased on the recommendation of the ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations to use mcg in place of \u03bcg, i.e., mc is used as the symbol for micro using the Latin alphabet.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Use of mc to represent micro in the ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations",
                    "resource-id": "https://www.ismp.org/recommendations/error-prone-abbreviations-list"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Micro-"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -6
                }
            },
            "x-optimade-definition": {
                "label": "micro_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "micro"
            }
        },
        "n": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/nano",
            "title": "nano",
            "symbol": "n",
            "display-symbol": "n",
            "description": "The nano SI prefix defined as a dimensionless multiple of 10\u207b\u2079, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Nano-"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -9
                }
            },
            "x-optimade-definition": {
                "label": "nano_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "nano"
            }
        },
        "p": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/pico",
            "title": "pico",
            "symbol": "p",
            "display-symbol": "p",
            "description": "The pico SI prefix defined as a dimensionless multiple of 10\u207b\u00b9\u00b2, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -12
                }
            },
            "x-optimade-definition": {
                "label": "pico_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "pico"
            }
        },
        "f": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/femto",
            "title": "femto",
            "symbol": "f",
            "display-symbol": "f",
            "description": "The femto SI prefix defined as a dimensionless multiple of 10\u207b\u00b9\u2075, defined at the 12th CGPM Meeting in 1964, resolution 8.",
            "resources": [
                {
                    "relation": "Definition in the 12th CGPM Meeting in 1964, resolution 8",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/12-1964/resolution-8"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -15
                }
            },
            "x-optimade-definition": {
                "label": "femto_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "femto"
            }
        },
        "a": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/atto",
            "title": "atto",
            "symbol": "a",
            "display-symbol": "a",
            "description": "The atto SI prefix defined as a dimensionless multiple of 10\u207b\u00b9\u2078, defined at the 12th CGPM Meeting in 1964, resolution 8.",
            "resources": [
                {
                    "relation": "Definition in the 12th CGPM Meeting in 1964, resolution 8",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/12-1964/resolution-8"
                },
                {
                    "relation": "Wikipedia article describing the SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -18
                }
            },
            "x-optimade-definition": {
                "label": "atto_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "atto"
            }
        },
        "z": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/zepto",
            "title": "zepto",
            "symbol": "z",
            "display-symbol": "z",
            "description": "The zepto SI prefix defined as a dimensionless multiple of 10\u207b\u00b2\u00b9, defined at the 19th CGPM Meeting in 1991, resolution 4.",
            "resources": [
                {
                    "relation": "Definition in the 19th CGPM Meeting in 1991, resolution 4",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/19-1991/resolution-4"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -21
                }
            },
            "x-optimade-definition": {
                "label": "zepto_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "zepto"
            }
        },
        "y": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/yocto",
            "title": "yocto",
            "symbol": "y",
            "display-symbol": "y",
            "description": "The yocto SI prefix defined as a dimensionless multiple of 10\u207b\u00b2\u2074, defined at the 19th CGPM Meeting in 1991, resolution 4.",
            "resources": [
                {
                    "relation": "Definition in the 19th CGPM Meeting in 1991, resolution 4",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/19-1991/resolution-4"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -24
                }
            },
            "x-optimade-definition": {
                "label": "yocto_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "yocto"
            }
        },
        "Q": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/quetta",
            "title": "quetta",
            "symbol": "Q",
            "display-symbol": "Q",
            "description": "The quetta SI prefix defined as a dimensionless multiple of 10\u00b3\u2070, defined at the 27th CGPM Meeting in 2022, resolution 3.",
            "resources": [
                {
                    "relation": "Definition in the 27th CGPM Meeting in 2022, resolution 3",
                    "resource-id": "https://www.bipm.org/en/cgpm-2022/resolution-3"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 30
                }
            },
            "x-optimade-definition": {
                "label": "quetta_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "quetta"
            }
        },
        "R": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/ronna",
            "title": "ronna",
            "symbol": "R",
            "display-symbol": "R",
            "description": "The ronna SI prefix defined as a dimensionless multiple of 10\u00b2\u2077, defined at the 27th CGPM Meeting in 2022, resolution 3.",
            "resources": [
                {
                    "relation": "Definition in the 27th CGPM Meeting in 2022, resolution 3",
                    "resource-id": "https://www.bipm.org/en/cgpm-2022/resolution-3"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 27
                }
            },
            "x-optimade-definition": {
                "label": "ronna_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "ronna"
            }
        },
        "r": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/ronto",
            "title": "ronto",
            "symbol": "r",
            "display-symbol": "r",
            "description": "The ronto SI prefix defined as a dimensionless multiple of 10^\u207b\u00b2\u2077, defined at the 27th CGPM Meeting in 2022, resolution 3.",
            "resources": [
                {
                    "relation": "Definition in the 27th CGPM Meeting in 2022, resolution 3",
                    "resource-id": "https://www.bipm.org/en/cgpm-2022/resolution-3"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -27
                }
            },
            "x-optimade-definition": {
                "label": "ronto_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "ronto"
            }
        },
        "q": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/quecto",
            "title": "quecto",
            "symbol": "q",
            "display-symbol": "q",
            "description": "The quecto SI prefix defined as a dimensionless multiple of 10\u207b\u00b3\u2070, defined at the 27th CGPM Meeting in 2022, resolution 3.",
            "resources": [
                {
                    "relation": "Definition in the 27th CGPM Meeting in 2022, resolution 3",
                    "resource-id": "https://www.bipm.org/en/cgpm-2022/resolution-3"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -30
                }
            },
            "x-optimade-definition": {
                "label": "quecto_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "quecto"
            }
        },
        "Ei": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/exbi",
            "title": "exbi",
            "symbol": "Ei",
            "display-symbol": "Ei",
            "description": "The exbi prefix as a dimensionless multiple of 2\u2076\u2070 is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.",
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "base": 2,
                    "exponent": 60
                }
            },
            "x-optimade-definition": {
                "label": "exbi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "exbi"
            }
        },
        "Gi": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/gibi",
            "title": "gibi",
            "symbol": "Gi",
            "display-symbol": "Gi",
            "description": "The gibi prefix as a dimensionless multiple of 2\u00b3\u2070 is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.",
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "base": 2,
                    "exponent": 30
                }
            },
            "x-optimade-definition": {
                "label": "gibi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "gibi"
            }
        },
        "Ki": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/kibi",
            "title": "kibi",
            "symbol": "Ki",
            "display-symbol": "Ki",
            "description": "The kibi prefix as a dimensionless multiple of 2\u00b9\u2070 = 1024 is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.",
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "base": 2,
                    "exponent": 10
                }
            },
            "x-optimade-definition": {
                "label": "kibi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "kibi"
            }
        },
        "Mi": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/mebi",
            "title": "mebi",
            "symbol": "Mi",
            "display-symbol": "Mi",
            "description": "The mebi prefix as a dimensionless multiple of 2\u00b2\u2070 is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.",
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "base": 2,
                    "exponent": 20
                }
            },
            "x-optimade-definition": {
                "label": "mebi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "mebi"
            }
        },
        "Pi": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/pebi",
            "title": "pebi",
            "symbol": "Pi",
            "display-symbol": "Pi",
            "description": "The pebi prefix as a dimensionless multiple of 2\u2075\u2070 is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.",
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "base": 2,
                    "exponent": 50
                }
            },
            "x-optimade-definition": {
                "label": "pebi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "pebi"
            }
        },
        "Ti": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/tebi",
            "title": "tebi",
            "symbol": "Ti",
            "display-symbol": "Ti",
            "description": "The tebi prefix as a dimensionless multiple of 2\u2074\u2070 is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.",
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "base": 2,
                    "exponent": 40
                }
            },
            "x-optimade-definition": {
                "label": "tebi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "tebi"
            }
        },
        "Yi": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/yobi",
            "title": "yobi",
            "symbol": "Yi",
            "display-symbol": "Yi",
            "description": "The yobi prefix as a dimensionless multiple of 2\u2078\u2070 is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.",
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "base": 2,
                    "exponent": 80
                }
            },
            "x-optimade-definition": {
                "label": "yobi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "yobi"
            }
        },
        "Zi": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/zebi",
            "title": "zebi",
            "symbol": "Zi",
            "display-symbol": "Zi",
            "description": "The zebi prefix as a dimensionless multiple of 2\u2077\u2070 is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.",
            "resources": [
                {
                    "relation": "Definition in the International System of Units (SI), 9th Edition",
                    "resource-id": "https://www.bipm.org/en/publications/si-brochure"
                },
                {
                    "relation": "Wikipedia article describing SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "base": 2,
                    "exponent": 70
                }
            },
            "x-optimade-definition": {
                "label": "zebi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "zebi"
            }
        }
    }
}
SI general (unitsystem)
