SI 1973 (unitsystem)

This page documents an OPTIMADE Unitsystem Definition. See https://schemas.optimade.org/ for more information.

ID: https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_1973
Definition name: si_1973

Unitsystem name: SI 1973
Description: The SI unit system as represented in the 2nd edition of the International System of Units.

The International System of Units (SI) is established and maintained by the General Conference on Weights and Measures (CGPM). This represents the SI unit system described in the 2nd edition of the International System of Units in 1973.

Formats: [JSON] [MD]

This unitsystem defines the following units:

This unitsystem defines the following prefixes:

JSON definition:

{
    "$id": "https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_1973",
    "$schema": "https://schemas.optimade.org/meta/v1.2/optimade/unitsystem_definition.json",
    "title": "SI 1973",
    "description": "The SI unit system as represented in the 2nd edition of the International System of Units.\n\nThe International System of Units (SI) is established and maintained by the General Conference on Weights and Measures (CGPM).\nThis represents the SI unit system described in the 2nd edition of the International System of Units in 1973.",
    "x-optimade-definition": {
        "label": "si_1973_unitsystem",
        "kind": "unitsystem",
        "format": "1.2",
        "version": "1.2.0",
        "name": "si_1973"
    },
    "units": {
        "s": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/second",
            "title": "second",
            "symbol": "s",
            "display-symbol": "s",
            "description": "The SI base unit of time defined as a specific fraction of the tropical year 1900 at the 11th CGPM Meeting in 1960.\n\n\"The second is the fraction 1/31556925.9747 of the tropical year for 1900 January 0 at 12 hours ephemeris time.\" [11th CGPM Meeting in 1960, resolution 9]\nThe second was included into SI at the 11th CGPM Meeting in 1960 in resolution 12.",
            "resources": [
                {
                    "relation": "Definition at the 11th CGPM meeting (1960), resolution 6.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-6"
                },
                {
                    "relation": "Establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Second"
                }
            ],
            "standard": {
                "name": "si",
                "year": 1960,
                "category": "base",
                "symbol": "s"
            },
            "x-optimade-definition": {
                "label": "second_si_1960_base",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "second"
            }
        },
        "m": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre",
            "title": "metre",
            "symbol": "m",
            "display-symbol": "m",
            "alternate-symbols": [
                "metre",
                "meter"
            ],
            "description": "The metre, or meter, is the SI base unit of length defined in terms of the wavelength of the radiation for a specific transition in krypton 86 as redefined at the 11th CGPM Meeting in 1960.\n\n\"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.\" [11th CGPM meeting (1960), resolution 6]\nThe metre was adopted into SI at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "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": "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": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Metre"
                }
            ],
            "standard": {
                "name": "si",
                "year": 1960,
                "category": "base",
                "symbol": "m"
            },
            "x-optimade-definition": {
                "label": "metre_si_1960_base",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "metre"
            }
        },
        "kg": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram",
            "title": "kilogram",
            "symbol": "kg",
            "display-symbol": "kg",
            "description": "The SI base unit of mass as defined as the mass of the international kilogram prototype, which was adopted into SI at the 11th CGPM Meeting in 1960.\n\n\"The prototype of the kilogram adopted by the International Committee; This prototype will henceforth be considered as the unit of mass;\", referring to the international prototype of the kilogram made of platinum-iridium [1st CGPM Meeting (1889)].\nThe kilogram was adopted into SI at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition at the 1st CGPM meeting (1889)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/1-1889"
                },
                {
                    "relation": "Establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Kilogram"
                }
            ],
            "standard": {
                "name": "si",
                "year": 1960,
                "category": "base",
                "symbol": "kg"
            },
            "x-optimade-definition": {
                "label": "kilogram_si_1960_base",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "kilogram"
            }
        },
        "A": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/ampere",
            "title": "ampere",
            "symbol": "A",
            "display-symbol": "A",
            "description": "The SI base unit of electric current defined from the force between parallel wires carrying an electric current at the 41st CIPM meeting (1946), resolution 2 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.\n\n\"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.\" [41st CIPM meeting (1946), Resolution 2].\n\nFurthermore, following the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1, the implicitly redefined ampere references:\n\n- the metre in the definition references the SI 1960 metre (https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre)\n- the MKS unit of force references the derived newton unit (https://schemas.optimade.org/defs/v1.2/units/si/1960/derived/newton) equal to kilogram\u00b7metre\u00b7second\u207b\u00b2, referencing the SI 1960 kilogram (https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram) and metre (https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre); and the 1967 definition of the second (https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second).",
            "resources": [
                {
                    "relation": "Definition at the 41st CIPM meeting (1946), resolution 2",
                    "resource-id": "https://www.bipm.org/en/committees/ci/cipm/41-1946/resolution-2"
                },
                {
                    "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": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Ampere"
                }
            ],
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "base",
                "symbol": "A"
            },
            "x-optimade-definition": {
                "label": "ampere_si_1967_base",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "ampere"
            }
        },
        "K": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/kelvin",
            "title": "kelvin",
            "symbol": "K",
            "display-symbol": "K",
            "description": "The kelvin is the SI base unit of thermodynamic temperature defined from the triple point of water at the 13th CGPM Meeting in 1967, resolution 3 and 4 and clarified at the 23rd CGPM Meeting in 2007, resolution 10.\n\nThe definition is functionally the same as the prior definition of degree Kelvin from the 10th CGPM meeting in 1954.\nHowever, at the 13th CGPM Meeting in 1967, resolution 4, the definition was rephrased as: \"The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water.\"\nIn this defining text, and as decided in resolution 3, the unit is named kelvin with the symbol K, replacing the prior use of degree Kelvin and variations.\n\nThe 23rd CGPM meeting in 2007, resolution 10, approved to append a clarification to the above definition: \"This definition refers to water having the isotopic composition defined by the following amount-of-substance ratios: 0.00015576 mole of \u00b2H per mole of \u00b9H, 0.0003799 mole of \u00b9\u2077O per mole of \u00b9\u2076O and 0.0020052 mole of \u00b9\u2078O per mole of \u00b9\u2076O.\"",
            "compatibility": [
                "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/degreekelvin"
            ],
            "resources": [
                {
                    "relation": "Definition at the 13th CGPM meeting (1967), resolution 4",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-4"
                },
                {
                    "relation": "Definition of the name kelvin and symbol K at the 13th CGPM meeting (1967), resolution 3",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-3"
                },
                {
                    "relation": "Clarification at the 23rd CGPM meeting (2007), resolution 10",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/23-2007/resolution-10"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Kelvin"
                }
            ],
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "base",
                "symbol": "K"
            },
            "x-optimade-definition": {
                "label": "kelvin_si_1967_base",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "kelvin"
            }
        },
        "cd": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/candela",
            "title": "candela",
            "symbol": "cd",
            "display-symbol": "cd",
            "description": "The candela is the SI base unit of luminous intensity in a given direction defined in from the radiation of a black body at the temperature of freezing platinum as defined at the 9th CGPM meeting in 1948, clarifed at the 13th CGPM Meeting in 1967, resolution 5; and implicitly redefined due to the 1967 SI redefinition of the second.\n\nAt the 13th CGPM Meeting in 1967, resolution 5 the previous definition from the 9th CGPM meeting in 1948 was rephrased to be more clear: \"The candela is the luminous intensity, in the perpendicular direction, of a surface of 1/600000 square metre of a black body at the temperature of freezing platinum under a pressure of 101325 newtons per square metre.\"\n\nFurthermore, the SI 1967 definition of the candela references:\n\n- the SI 1960 metre (https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre).\n- the SI 1967 derived newton unit (https://schemas.optimade.org/defs/v1.2/units/si/1967/named/newton) equal to kilogram\u00b7metre\u00b7second\u207b\u00b2, referencing the SI 1960 kilogram (https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram) and metre (https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre); and the 1967 definition of the second (https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second).",
            "resources": [
                {
                    "relation": "Definition at the 13th CGPM meeting (1967)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-5"
                },
                {
                    "relation": "Previous definition at the 9th CGPM meeting (1948)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Candela"
                }
            ],
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "base",
                "symbol": "cd"
            },
            "x-optimade-definition": {
                "label": "candela_si_1967_base",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "candela"
            }
        },
        "mol": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1971/base/mole",
            "title": "mole",
            "symbol": "mol",
            "display-symbol": "mol",
            "description": "The SI base unit of amount of substance defined via the number of atoms in 12 grams of carbon 12 at the 14th CGPM Meeting in 1971 and clarified at the 69th CIPM meeting in 1980.\n\n\"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.\" [14th CGPM Meeting (1971), resolution 3].\n\nThe 69th CIPM meeting in 1980 approved to append a clarification to the above definition: \"In this definition, it is understood that unbound atoms of carbon 12, at rest and in their ground state, are referred to.\"",
            "resources": [
                {
                    "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": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Mole_(unit)"
                }
            ],
            "standard": {
                "name": "si",
                "year": 1971,
                "category": "base",
                "symbol": "mol"
            },
            "x-optimade-definition": {
                "label": "mole_si_1971_base",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "mole"
            }
        },
        "rad": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/supplementary/radian",
            "title": "radian",
            "symbol": "rad",
            "display-symbol": "rad",
            "description": "An SI unit of plane angle defined from 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.\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.",
            "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"
                }
            ],
            "standard": {
                "name": "si",
                "year": 1960,
                "category": "supplementary",
                "symbol": "rad"
            },
            "x-optimade-definition": {
                "label": "radian_si_1960_supplementary",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "radian"
            }
        },
        "sr": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/supplementary/steradian",
            "title": "steradian",
            "symbol": "sr",
            "display-symbol": "sr",
            "alternate-symbols": [
                "sterad"
            ],
            "description": "A supplementary SI unit of solid angle defined from 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, defined at the 9th CGPM Meeting in 1948 and included into SI at the 11th CGPM Meeting in 1960.\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.",
            "resources": [
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                    "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"
                }
            ],
            "standard": {
                "name": "si",
                "year": 1960,
                "category": "supplementary",
                "symbol": "sr"
            },
            "x-optimade-definition": {
                "label": "steradian_si_1960_supplementary",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "steradian"
            }
        },
        "Hz": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/hertz",
            "title": "hertz",
            "symbol": "Hz",
            "display-symbol": "Hz",
            "description": "A derived SI unit for frequency equal to s\u207b\u00b9 in the 1967 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.",
            "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/1967/base/second"
                    }
                ],
                "base-units-expression": "s^-1"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "Hz"
            },
            "x-optimade-definition": {
                "label": "hertz_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "hertz"
            }
        },
        "N": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/newton",
            "title": "newton",
            "symbol": "N",
            "display-symbol": "N",
            "description": "The newton is a derived SI unit for force and weight equal to kg\u00b7m\u00b7s\u207b\u00b2 in 1967 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 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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": "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/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "kg*m*s^-2"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "N"
            },
            "x-optimade-definition": {
                "label": "newton_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "newton"
            }
        },
        "Pa": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1971/named/pascal",
            "title": "pascal",
            "symbol": "Pa",
            "display-symbol": "Pa",
            "description": "A derived SI unit for pressure and stress equal to kg\u00b7m\u207b\u00b9\u00b7s\u207b\u00b2 using the 1967 SI base units, defined at the 14th CGPM Meeting (1971).\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)].",
            "resources": [
                {
                    "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)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "kg*m^-1*s^-2"
            },
            "standard": {
                "name": "si",
                "year": 1971,
                "category": "named",
                "symbol": "Pa"
            },
            "x-optimade-definition": {
                "label": "pascal_si_1971_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "pascal"
            }
        },
        "J": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/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 in the 1967 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 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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/Joule"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "kg*m^2*s^-2"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "J"
            },
            "x-optimade-definition": {
                "label": "joule_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "joule"
            }
        },
        "W": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/watt",
            "title": "watt",
            "symbol": "W",
            "display-symbol": "W",
            "description": "A derived SI unit for power and radiant flux equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b3 in the 1967 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 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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/Watt"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "kg*m^2*s^-3"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "W"
            },
            "x-optimade-definition": {
                "label": "watt_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "watt"
            }
        },
        "C": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/coulomb",
            "title": "coulomb",
            "symbol": "C",
            "display-symbol": "C",
            "description": "A derived SI unit for electric charge equal to s\u00b7A in the 1967 SI base 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 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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/Coulomb"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    },
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/ampere"
                    }
                ],
                "base-units-expression": "A*s"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "C"
            },
            "x-optimade-definition": {
                "label": "coulomb_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "coulomb"
            }
        },
        "V": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/volt",
            "title": "volt",
            "symbol": "V",
            "display-symbol": "V",
            "description": "A derived SI unit for electric potential, voltage, and electromotive force equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b3\u00b7A\u207b\u00b9 in the 1967 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 redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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/Volt"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    },
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/ampere"
                    }
                ],
                "base-units-expression": "A^-1*kg*m^2*s^-3"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "V"
            },
            "x-optimade-definition": {
                "label": "volt_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "volt"
            }
        },
        "F": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/farad",
            "title": "farad",
            "symbol": "F",
            "display-symbol": "F",
            "description": "A derived SI unit for electrical capacitance equal to kg\u207b\u00b9\u00b7m\u207b\u00b2\u00b7s\u2074\u00b7A\u00b2 in the 1967 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 redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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": "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/1967/base/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "A^2*kg^-1*m^-2*s^4"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "F"
            },
            "x-optimade-definition": {
                "label": "farad_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "farad"
            }
        },
        "ohm": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/ohm",
            "title": "ohm",
            "symbol": "ohm",
            "display-symbol": "\u03a9",
            "description": "A derived SI unit for electrical resistance equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b3\u00b7A\u207b\u00b2 in the 1967 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 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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/Ohm"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "A^-2*kg*m^2*s^-3"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "ohm"
            },
            "x-optimade-definition": {
                "label": "ohm_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "ohm"
            }
        },
        "S": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1971/named/siemens",
            "title": "siemens",
            "symbol": "S",
            "display-symbol": "S",
            "description": "A derived SI unit for electrical conductance equal to kg\u207b\u00b9\u00b7m\u207b\u00b2\u00b7s\u00b3\u00b7A\u00b2 using the 1967 SI base units, defined at the 14th CGPM Meeting (1971).\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)].",
            "resources": [
                {
                    "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/Siemens_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "A^2*kg^-1*m^-2*s^3"
            },
            "standard": {
                "name": "si",
                "year": 1971,
                "category": "named",
                "symbol": "S"
            },
            "x-optimade-definition": {
                "label": "siemens_si_1971_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "siemens"
            }
        },
        "Wb": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/weber",
            "title": "weber",
            "symbol": "Wb",
            "display-symbol": "Wb",
            "description": "A derived SI unit for magnetic flux equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b3\u00b7A\u207b\u00b9 in the 1967 SI base 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 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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/Weber_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "A^-1*kg*m^2*s^-3"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "Wb"
            },
            "x-optimade-definition": {
                "label": "weber_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "weber"
            }
        },
        "T": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/tesla",
            "title": "tesla",
            "symbol": "T",
            "display-symbol": "T",
            "description": "A derived SI unit for magnetic flux density equal to kg\u00b7s\u207b\u00b2\u00b7A\u207b\u00b9 in the 1967 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 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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": "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/1967/base/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "A^-1*kg*s^-2"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "T"
            },
            "x-optimade-definition": {
                "label": "tesla_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "tesla"
            }
        },
        "H": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/henry",
            "title": "henry",
            "symbol": "H",
            "display-symbol": "H",
            "description": "A derived SI unit for inductance equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b2\u00b7A\u207b\u00b2 in the 1967 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 redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
            "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/Henry_(unit)"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "A",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/ampere"
                    },
                    {
                        "symbol": "kg",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    },
                    {
                        "symbol": "s",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
                    }
                ],
                "base-units-expression": "A^-2*kg*m^2*s^-2"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "H"
            },
            "x-optimade-definition": {
                "label": "henry_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "henry"
            }
        },
        "degC": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/degcelsius",
            "title": "Degree Celsius",
            "symbol": "degC",
            "display-symbol": "\u00b0C",
            "alternate-symbols": [
                "degcelsius"
            ],
            "description": "A derived SI unit of temperature, defined as degree kelvin offset with +273.15 in 1967 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 redefinition of the kelvin at the 13th CGPM Meeting in 1967, resolution 4.",
            "resources": [
                {
                    "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": "Definition of the kelvin at the 11th CGPM meeting (1960)",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960"
                },
                {
                    "relation": "Wikipedia article describing the unit",
                    "resource-id": "https://en.wikipedia.org/wiki/Celsius"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "degK",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/kelvin"
                    }
                ],
                "base-units-expression": "degK",
                "offset": {
                    "numerator": 27315,
                    "denominator": 100
                }
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "degC"
            },
            "x-optimade-definition": {
                "label": "degcelsius_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "degcelsius"
            }
        },
        "lm": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/lumen",
            "title": "lumen",
            "symbol": "lm",
            "display-symbol": "lm",
            "description": "A derived SI unit for luminous flux equal to cd\u00b7sr in the 1967 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, 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.",
            "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": "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/1967/base/candela"
                    },
                    {
                        "symbol": "sr",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/supplementary/steradian"
                    }
                ],
                "base-units-expression": "cd*sr"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "lm"
            },
            "x-optimade-definition": {
                "label": "lumen_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "lumen"
            }
        },
        "lx": {
            "$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/lux",
            "title": "lux",
            "symbol": "lx",
            "display-symbol": "lx",
            "description": "A derived SI unit for illuminance equal to cd\u22c5sr\u22c5m\u207b\u00b2 in 1967 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, 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.",
            "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/Lux"
                }
            ],
            "defining-relation": {
                "base-units": [
                    {
                        "symbol": "cd",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/candela"
                    },
                    {
                        "symbol": "sr",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/supplementary/steradian"
                    },
                    {
                        "symbol": "m",
                        "id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
                    }
                ],
                "base-units-expression": "cd*m^-2*sr"
            },
            "standard": {
                "name": "si",
                "year": 1967,
                "category": "named",
                "symbol": "lx"
            },
            "x-optimade-definition": {
                "label": "lux_si_1967_named",
                "kind": "unit",
                "format": "1.2",
                "version": "1.2.0",
                "name": "lux"
            }
        }
    },
    "prefixes": {
        "T": {
            "$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 11:th 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": "tera_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "tera"
            }
        },
        "G": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/giga",
            "title": "giga",
            "symbol": "G",
            "display-symbol": "G",
            "description": "The giga SI prefix defined as a dimensionless multiple of 10\u2079, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11:th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Giga-"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 9
                }
            },
            "x-optimade-definition": {
                "label": "giga_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "giga"
            }
        },
        "M": {
            "$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 11:th 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-"
                }
            ],
            "defining-relation": {
                "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"
            }
        },
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            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/kilo",
            "title": "kilo",
            "symbol": "k",
            "display-symbol": "k",
            "description": "The kilo SI prefix defined as a dimensionless multiple of 10\u00b3, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11:th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Kilo-"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 3
                }
            },
            "x-optimade-definition": {
                "label": "kilo_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "kilo"
            }
        },
        "h": {
            "$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 11:th 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-"
                }
            ],
            "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": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/deca",
            "title": "deca",
            "symbol": "da",
            "display-symbol": "da",
            "description": "The deca SI prefix defined as a dimensionless multiple of 10, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11:th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Deca-"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": 1
                }
            },
            "x-optimade-definition": {
                "label": "deca_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "deca"
            }
        },
        "d": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/deci",
            "title": "deci",
            "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": [
                {
                    "relation": "Definition in the 11:th 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/Deci-"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -1
                }
            },
            "x-optimade-definition": {
                "label": "deci_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "deci"
            }
        },
        "c": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/centi",
            "title": "centi",
            "symbol": "c",
            "display-symbol": "c",
            "description": "The centi SI prefix defined as a dimensionless multiple of 10\u207b\u00b2, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11:th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Centi-"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -2
                }
            },
            "x-optimade-definition": {
                "label": "centi_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "centi"
            }
        },
        "m": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/milli",
            "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 11:th 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-"
                }
            ],
            "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": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/micro",
            "title": "micro",
            "symbol": "mc",
            "display-symbol": "\u03bc",
            "description": "The micro SI prefix defined as a dimensionless multiple of 10\u207b\u2076, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.\n\nThe micro SI prefix is the only one using a non Latin symbol.\nBased on the recommendation of the ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations to use mcg in place of \u03bcg, i.e., mc is used as the symbol for micro using the Latin alphabet.",
            "resources": [
                {
                    "relation": "Definition in the 11:th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Use of mc to represent micro in the ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations",
                    "resource-id": "https://www.ismp.org/recommendations/error-prone-abbreviations-list"
                },
                {
                    "relation": "Wikipedia article describing the prefix",
                    "resource-id": "https://en.wikipedia.org/wiki/Micro-"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -6
                }
            },
            "x-optimade-definition": {
                "label": "micro_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "micro"
            }
        },
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            "$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 11:th 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": {
            "$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/pico",
            "title": "pico",
            "symbol": "p",
            "display-symbol": "p",
            "description": "The pico SI prefix defined as a dimensionless multiple of 10\u207b\u00b9\u00b2, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
            "resources": [
                {
                    "relation": "Definition in the 11:th CGPM Meeting in 1960, resolution 12",
                    "resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
                },
                {
                    "relation": "Wikipedia article describing the SI prefixes",
                    "resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
                }
            ],
            "defining-relation": {
                "base-units": [],
                "base-units-expression": "",
                "scale": {
                    "exponent": -12
                }
            },
            "x-optimade-definition": {
                "label": "pico_prefix_si",
                "kind": "prefix",
                "format": "1.2",
                "version": "1.2.0",
                "name": "pico"
            }
        },
        "f": {
            "$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 12:th 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 12:th 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"
            }
        }
    }
}