v1.2
constants
codata
electromagnetic
Bohr magneton (constant) - https://schemas.optimade.org/defs/v1.2/constants/codata/2018/electromagnetic/bohrmagneton
The 2018 CODATA Bohr magneton constant is defined as "1 = 9.274 010 0783(28)·10^-24 J·T^-1" with joule and tesla conforming to the 2019 redefinition of the SI derived units.
elementary charge (constant) - https://schemas.optimade.org/defs/v1.2/constants/codata/2018/electromagnetic/elementarycharge
The CODATA 2018 value for the absolute value of the charge of the electron.
math
pi (constant) - https://schemas.optimade.org/defs/v1.2/constants/math/basic/pi
The ratio of a circle's circumference to its diameter. Approximately equal to 3.1415926.
entrytypes
optimade
files (entrytype) - https://schemas.optimade.org/defs/v1.2/entrytypes/optimade/files
The files entry type describes a file with metadata and a URL to retrieve it
references (entrytype) - https://schemas.optimade.org/defs/v1.2/entrytypes/optimade/references
The references entry type describes a reference
structures (entrytype) - https://schemas.optimade.org/defs/v1.2/entrytypes/optimade/structures
The structures entry type describes a crystal structure via its unit cell
prefixes
si
atto (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/atto
The atto SI prefix defined as a dimensionless multiple of 10⁻¹⁸, defined at the 12th CGPM Meeting in 1964, resolution 8.
centi (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/centi
The centi SI prefix defined as a dimensionless multiple of 10⁻², adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
deca (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/deca
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.
deci (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/deci
The deci SI prefix defined as a dimensionless multiple of 10⁻¹, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
exa (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/exa
The exa SI prefix defined as a dimensionless multiple of 10¹⁸, defined at the 15th CGPM Meeting in 1975, resolution 10.
exbi (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/exbi
The exbi prefix as a dimensionless multiple of 2⁶⁰ is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.
femto (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/femto
The femto SI prefix defined as a dimensionless multiple of 10⁻¹⁵, defined at the 12th CGPM Meeting in 1964, resolution 8.
gibi (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/gibi
The gibi prefix as a dimensionless multiple of 2³⁰ is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.
giga (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/giga
The giga SI prefix defined as a dimensionless multiple of 10⁹, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
hecto (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/hecto
The hecto SI prefix defined as a dimensionless multiple of 10², adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
kibi (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/kibi
The kibi prefix as a dimensionless multiple of 2¹⁰ = 1024 is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.
kilo (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/kilo
The kilo SI prefix defined as a dimensionless multiple of 10³, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
mebi (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/mebi
The mebi prefix as a dimensionless multiple of 2²⁰ is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.
mega (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/mega
The mega SI prefix defined as a dimensionless multiple of 10⁶, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
micro (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/micro
The micro SI prefix defined as a dimensionless multiple of 10⁻⁶, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
milli (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/milli
The milli SI prefix defined as a dimensionless multiple of 10⁻³, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
nano (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/nano
The nano SI prefix defined as a dimensionless multiple of 10⁻⁹, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
pebi (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/pebi
The pebi prefix as a dimensionless multiple of 2⁵⁰ is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.
peta (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/peta
The peta SI prefix defined as a dimensionless multiple of 10¹⁵, defined at the 15th CGPM Meeting in 1975, resolution 10.
pico (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/pico
The pico SI prefix defined as a dimensionless multiple of 10⁻¹², adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
quecto (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/quecto
The quecto SI prefix defined as a dimensionless multiple of 10⁻³⁰, defined at the 27th CGPM Meeting in 2022, resolution 3.
quetta (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/quetta
The quetta SI prefix defined as a dimensionless multiple of 10³⁰, defined at the 27th CGPM Meeting in 2022, resolution 3.
ronna (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/ronna
The ronna SI prefix defined as a dimensionless multiple of 10²⁷, defined at the 27th CGPM Meeting in 2022, resolution 3.
ronto (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/ronto
The ronto SI prefix defined as a dimensionless multiple of 10^⁻²⁷, defined at the 27th CGPM Meeting in 2022, resolution 3.
tebi (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/tebi
The tebi prefix as a dimensionless multiple of 2⁴⁰ is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.
tera (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/tera
The tera SI prefix defined as a dimensionless multiple of 10¹², adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.
yobi (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/yobi
The yobi prefix as a dimensionless multiple of 2⁸⁰ is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.
yocto (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/yocto
The yocto SI prefix defined as a dimensionless multiple of 10⁻²⁴, defined at the 19th CGPM Meeting in 1991, resolution 4.
yotta (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/yotta
The yotta SI prefix defined as a dimensionless multiple of 10²⁴, defined at the 19th CGPM Meeting in 1991, resolution 4.
zebi (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/zebi
The zebi prefix as a dimensionless multiple of 2⁷⁰ is one of a set of recommended prefixes in the International System of Units (SI), 9th Edition for referring to powers of 2.
zepto (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/zepto
The zepto SI prefix defined as a dimensionless multiple of 10⁻²¹, defined at the 19th CGPM Meeting in 1991, resolution 4.
zetta (prefix) - https://schemas.optimade.org/defs/v1.2/prefixes/si/zetta
The zetta SI prefix defined as a dimensionless multiple of 10²¹, defined at the 19th CGPM Meeting in 1991, resolution 4.
properties
core
features (property) - https://schemas.optimade.org/defs/v1.2/properties/core/features
A list of strings that flag which special features are used by the entry.
ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/id
A unique string referencing a specific entry in the database.
immutable ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/immutable_id
The entry's immutable ID (e.g., a UUID).
last modified (property) - https://schemas.optimade.org/defs/v1.2/properties/core/last_modified
Date and time representing when the entry was last modified.
type (property) - https://schemas.optimade.org/defs/v1.2/properties/core/type
The name of the type of an entry.
optimade
calculations
ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/id
A unique string referencing a specific entry in the database.
immutable ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/immutable_id
The entry's immutable ID (e.g., a UUID).
last modified (property) - https://schemas.optimade.org/defs/v1.2/properties/core/last_modified
Date and time representing when the entry was last modified.
type (property) - https://schemas.optimade.org/defs/v1.2/properties/core/type
The name of the type of an entry.
common
chemical symbol (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/common/chemical_symbol
A chemical symbol referring to an element or a non-chemical element.
chemical symbol or vacancy (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/common/chemical_symbol_or_vacancy
A chemical symbol referring to an element, a non-chemical element, or a vacancy.
element (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/common/element
The chemical symbol of an element
person (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/common/person
A dictionary with name information about a person.
space group symmetry operation (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/common/space_group_symmetry_operation_xyz
A single symmetry operation.
name of the species (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/common/species_name
The name of the species.
symmetry operation (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/common/symmetry_operation_xyz
A symmetry operation given as general position x, y, z coordinates in algebraic form.
files
access time (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/atime
Time of last access of a file as per POSIX standard.
checksums (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/checksums
Dictionary providing checksums of file contents.
change time (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/ctime
Time of last status change of a file as per POSIX standard.
description (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/description
Free-form description of a file.
ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/id
A unique string referencing a specific entry in the database.
immutable ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/immutable_id
The entry's immutable ID (e.g., a UUID).
last modified (property) - https://schemas.optimade.org/defs/v1.2/properties/core/last_modified
Date and time representing when the entry was last modified.
media type (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/media_type
Media type identifier (also known as MIME type), for a file as per RFC 6838 Media Type Specifications and Registration Procedures.
modification timestamp (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/modification_timestamp
Timestamp of the last modification of file contents. A modification is understood as an addition, change or deletion of one or more bytes, resulting in file contents different from the previous.
modification time (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/mtime
Time of last modification of a file as per POSIX standard.
name (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/name
Base name of a file.
size (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/size
Size of a file in bytes.
type (property) - https://schemas.optimade.org/defs/v1.2/properties/core/type
The name of the type of an entry.
URL (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/url
The URL to get the contents of a file.
URL stable until (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/url_stable_until
Point in time until which the URL in url
is guaranteed to stay stable.
version (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/files/version
Version information of a file (e.g., commit, revision, timestamp).
references
address (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/address
Typically the location of the publisher or institution (the address field in the BibTeX specification).
annote (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/annote
Additional notes or comments on the reference (the annote field in the BibTeX specification).
authors (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/authors
A list of dictionaries with names of the authors.
bibliographic type (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/bib_type
Type of the reference (the type field in the BibTeX specification).
booktitle (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/booktitle
The title of a book being cited; for parts of a book, use the title field instead (the booktitle field in the BibTeX specification).
chapter (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/chapter
The chapter, section, or similar part number (the chapter field in the BibTeX specification).
crossref (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/crossref
The database key of the entry being cross referenced (the crossref field in the BibTeX specification).
doi (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/doi
The doi identifier of the object being referenced.
edition (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/edition
The edition of a book (the edition field in the BibTeX specification).
editors (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/editors
A list of dictionaries with names of the editors.
how published (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/howpublished
The method of publication (the howpublished field in the BibTeX specification)
ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/id
A unique string referencing a specific entry in the database.
immutable ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/immutable_id
The entry's immutable ID (e.g., a UUID).
institution (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/institution
The sponsoring institution of a technical report (the institution field in the BibTeX specification).
journal (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/journal
The name of a journal (the journal field in the BibTeX specification).
key (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/key
Used for alphabetizing, cross-referencing, and creating a label (the key field in the BibTeX specification).
last modified (property) - https://schemas.optimade.org/defs/v1.2/properties/core/last_modified
Date and time representing when the entry was last modified.
month (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/month
The three-letter abbreviation of the month of publication or writing (the month field in the BibTeX specification).
note (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/note
Additional information about the reference (the note field in the BibTeX specification).
number (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/number
The number of a journal, magazine, technical report, or work in a series (the number field in the BibTeX specification).
organization (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/organization
The organization sponsoring a conference or publishing a manual (the organization field in the BibTeX specification)
pages (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/pages
The page number(s) of the reference (the pages field in the BibTeX specification).
publisher (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/publisher
The name of the publisher (the publisher field in the BibTeX specification).
school (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/school
The name of the school where a thesis was written (the school field in the BibTeX specification).
series (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/series
The name of a series or set of books (the series field in the BibTeX specification).
title (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/title
The title of the work (the title field in the BibTeX specification).
type (property) - https://schemas.optimade.org/defs/v1.2/properties/core/type
The name of the type of an entry.
URL (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/url
The URL of the object being referenced.
volume (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/volume
The volume number of a journal or multivolume book (the volume field in the BibTeX specification).
year (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/references/year
The year of publication or writing.
structures
assemblies (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/assemblies
A description of groups of sites that are statistically correlated.
Cartesian site positions (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/cartesian_site_positions
Cartesian positions of each site in the structure.
anonymous chemical formula (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/chemical_formula_anonymous
The anonymous formula is the chemical_formula_reduced, but where the elements are instead first ordered by their chemical proportion number, and then, in order left to right, replaced by anonymous symbols A, B, C, ..., Z, Aa, Ba, ..., Za, Ab, Bb, ... and so on.
descriptive chemical formula (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/chemical_formula_descriptive
The chemical formula for a structure as a string in a form chosen by the API implementation.
Hill chemical formula (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/chemical_formula_hill
The chemical formula for a structure in Hill form with element symbols followed by integer chemical proportion numbers. The proportion number MUST be omitted if it is 1.
reduced chemical formula (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/chemical_formula_reduced
The reduced chemical formula for a structure as a string with element symbols and integer chemical proportion numbers.
dimension types (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/dimension_types
List of three integers describing the periodicity of the boundaries of the unit cell. For each direction indicated by the three lattice_vectors, this list indicates if the direction is periodic (value 1) or non-periodic (value 0). Note: the elements in this list each refer to the direction of the corresponding entry in lattice_vectors and not the Cartesian x, y, z directions.
elements (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/elements
The chemical symbols of the different elements present in the structure.
elements ratios (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/elements_ratios
Relative proportions of different elements in the structure.
ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/id
A unique string referencing a specific entry in the database.
immutable ID (property) - https://schemas.optimade.org/defs/v1.2/properties/core/immutable_id
The entry's immutable ID (e.g., a UUID).
last modified (property) - https://schemas.optimade.org/defs/v1.2/properties/core/last_modified
Date and time representing when the entry was last modified.
lattice vectors (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/lattice_vectors
The three lattice vectors in Cartesian coordinates, in ångström (Å).
number of elements (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/nelements
Number of different elements in the structure as an integer.
number of periodic dimensions (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/nperiodic_dimensions
An integer specifying the number of periodic dimensions in the structure, equivalent to the number of non-zero entries in dimension_types
.
number of sites (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/nsites
An integer specifying the length of the cartesian_site_positions
property.
space group IT number (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/space_group_it_number
Space group number for the structure assigned by the International Tables for Crystallography Vol. A.
Hall space group symbol (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/space_group_symbol_hall
A Hall space group symbol representing the symmetry of the structure as defined in Hall, S. R. (1981), Acta Cryst. A37, 517-525 and erratum (1981), A37, 921.
Hermann-Mauguin space group symbol (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/space_group_symbol_hermann_mauguin
A human- and machine-readable string containing the short Hermann-Mauguin (H-M) symbol which specifies the space group of the structure in the response.
extended Hermann-Mauguin space group symbol (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/space_group_symbol_hermann_mauguin_extended
A human- and machine-readable string containing the extended Hermann-Mauguin (H-M) symbol which specifies the space group of the structure in the response.
space group symmetry operations (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/space_group_symmetry_operations_xyz
A list of symmetry operations given as general position x, y and z coordinates in algebraic form.
species (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/species
A list describing the species of the sites of this structure. Species can represent pure chemical elements, virtual-crystal atoms representing a statistical occupation of a given site by multiple chemical elements, and/or a location to which there are attached atoms, i.e., atoms whose precise location are unknown beyond that they are attached to that position (frequently used to indicate hydrogen atoms attached to another element, e.g., a carbon with three attached hydrogens might represent a methyl group, -CH3).
species at sites (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/species_at_sites
Name of the species at each site (where values for sites are specified with the same order of the property cartesian_site_positions
). The properties of the species are found in the property species
.
structure features (property) - https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/structure_features
A list of strings that flag which special features are used by the structure.
type (property) - https://schemas.optimade.org/defs/v1.2/properties/core/type
The name of the type of an entry.
standards
OPTIMADE standard (standard) - https://schemas.optimade.org/defs/v1.2/standards/optimade
The OPTIMADE standard node types and properties
units
codata
Bohr magneton (unit) - https://schemas.optimade.org/defs/v1.2/units/codata/1969/electromagnetic/bohrmagneton
A unit expressing the magnetic moment of an electron caused by its orbital or spin angular momentum defined as part of CODATA 1969.
independent
bit (unit) - https://schemas.optimade.org/defs/v1.2/units/independent/1948/information/bit
A basic unit of digital information representing a single logical state with one of two possible values, defined by Shannon in 1948.
iso-iec-80000
byte (unit) - https://schemas.optimade.org/defs/v1.2/units/iso-iec-80000/2008/information_science_and_technology/byte
A unit of digital information representing eight bits, defined in the International System of Quantities in ISO/IEC 80000-13 (2008).
si
1960
base
ampere (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/base/ampere
The SI base unit of electric current defined from the force between parallel wires carrying an electric current, which was included in the SI at the 11th CGPM Meeting in 1960.
candela (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/base/candela
The SI base unit of luminous intensity in a given direction defined from the radiation of a black body at the solidification temperature of platinum, which was included into SI at the 11th CGPM Meeting in 1960.
degree Kelvin (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/base/degreekelvin
The base SI unit of thermodynamic temperature defined from the triple point of water, which was adopted into SI at the 11th CGPM Meeting in 1960, resolution 12.
kilogram (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram
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.
metre (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre
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.
second (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/base/second
The SI base unit of time defined as a specific fraction of the tropical year 1900 at the 11th CGPM Meeting in 1960.
named
coulomb (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/coulomb
A derived SI unit for electric charge, equal to s·A in the 1960 SI base units.
degree Celsius (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/degcelsius
A derived SI unit of temperature, defined as degree kelvin offset with +273.15 in the SI base units adopted at the 11th CGPM Meeting in 1960.
farad (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/farad
A derived SI unit for electrical capacitance equal to kg⁻¹·m⁻²·s⁴·A² in the 1960 SI base units.
henry (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/henry
A derived SI unit for inductance equal to kg·m²·s⁻²·A⁻² in the 1960 SI base units.
hertz (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/hertz
A derived SI unit for frequency equal to s⁻¹ in the 1960 SI base units.
joule (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/joule
A derived SI unit for energy, work, and heat equal to kg·m²·s⁻² in the 1960 SI base units.
lumen (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/lumen
A derived SI unit for luminous flux equal to cd·sr in the 1960 SI base units.
lux (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/lux
A derived SI unit for illuminance equal to cd⋅sr⋅m⁻² in the 1960 SI base units.
newton (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/newton
A derived SI unit for force and weight equal to kg·m·s⁻² in the 1960 SI base units.
ohm (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/ohm
A derived SI unit for electrical resistance equal to kg·m²·s⁻³·A⁻² in the 1960 SI base units.
tesla (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/tesla
The tesla is a derived SI unit for magnetic flux density equal to kg·s⁻²·A⁻¹ in the 1960 SI base units.
volt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/volt
The volt is a derived SI unit for electric potential, voltage, and electromotive force equal to kg·m²·s⁻³·A⁻¹ in the 1960 SI base units.
watt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/watt
A derived SI unit for power and radiant flux equal to kg·m²·s⁻³ in the 1960 SI base units.
weber (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/named/weber
A derived SI unit for magnetic flux equal to kg·m²·s⁻³·A⁻¹ in the 1960 SI base units.
supplementary
radian (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/supplementary/radian
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 4π radians.
steradian (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1960/supplementary/steradian
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 4π steradians, defined at the 9th CGPM Meeting in 1948 and included into SI at the 11th CGPM Meeting in 1960.
1964
accepted
litre (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1964/accepted/litre
The litre, or liter is a unit of volume equal to a cubic decimetre (1 dm³), with meter defined according to the 1960 SI units.
temporary
curie (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1964/temporary/curie
A non-SI unit of activity with the value 3.7·10⁻¹⁰ s⁻¹ defined at the 12th CGPM meeting in 1964.
1967
base
ampere (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/base/ampere
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.
candela (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/base/candela
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, clarified at the 13th CGPM Meeting in 1967, resolution 5; and implicitly redefined due to the 1967 SI redefinition of the second.
kelvin (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/base/kelvin
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.
second (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second
The SI base unit of time defined via the periods of transitions between levels in the caesium 133 atom after the redefinition at the 13th CGPM Meeting in 1967.
named
coulomb (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/coulomb
A derived SI unit for electric charge equal to s·A in the 1967 SI base units.
degree Celsius (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/degcelsius
A derived SI unit of temperature, defined as degree kelvin offset with +273.15 in 1967 SI units.
farad (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/farad
A derived SI unit for electrical capacitance equal to kg⁻¹·m⁻²·s⁴·A² in the 1967 SI units.
henry (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/henry
A derived SI unit for inductance equal to kg·m²·s⁻²·A⁻² in the 1967 SI units.
hertz (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/hertz
A derived SI unit for frequency equal to s⁻¹ in the 1967 SI units.
joule (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/joule
A derived SI unit for energy, work, and heat equal to kg·m²·s⁻² in the 1967 SI units.
lumen (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/lumen
A derived SI unit for luminous flux equal to cd·sr in the 1967 SI units.
lux (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/lux
A derived SI unit for illuminance equal to cd⋅sr⋅m⁻² in 1967 SI units.
newton (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/newton
The newton is a derived SI unit for force and weight equal to kg·m·s⁻² in 1967 SI units.
ohm (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/ohm
A derived SI unit for electrical resistance equal to kg·m²·s⁻³·A⁻² in the 1967 SI units.
tesla (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/tesla
A derived SI unit for magnetic flux density equal to kg·s⁻²·A⁻¹ in the 1967 SI units.
volt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/volt
A derived SI unit for electric potential, voltage, and electromotive force equal to kg·m²·s⁻³·A⁻¹ in the 1967 SI units.
watt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/watt
A derived SI unit for power and radiant flux equal to kg·m²·s⁻³ in the 1967 SI units.
weber (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/named/weber
A derived SI unit for magnetic flux equal to kg·m²·s⁻³·A⁻¹ in the 1967 SI base units.
temporary
curie (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1967/temporary/curie
A non-SI unit of activity with the value 3.7·10⁻¹⁰ s⁻¹ in the 1967 SI units.
1970
accepted
arcminute (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/arcminute
A unit of plane and phase angle equal to 1/60 of a degree which is 1/21600 of a circle and equivalent to pi/10800 rad, with rad defined according to the 1960 supplementary SI unit.
arcsecond (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/arcsecond
A unit of plane and phase angle equal to 1/60 of an arcminute, which is 1/1296000 of a circle and equivalent to pi/648000 rad, with rad defined according to the 1960 supplementary SI unit.
astronomical unit (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/astronomicalunit
A length representing the mean distance between the Earth and the Sun defined via the circular orbit radius for a body with a specific angular velocity.
standard atmosphere (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/atmosphere
A pressure approximately equal to the average atmospheric pressure at sea level on Earth, defined as 101325 Pa using the 1967 SI units.
atomic mass unit (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/atomicmassunit
A unit of mass defined as 1/12 of the mass of a free carbon 12 atom, at rest and in its ground state.
day (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/day
A unit of time equal to 86 400 seconds, using the 1967 base SI units.
degree (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/degree
A unit of plane and phase angle where a full circle is 360 degrees, which is equivalent to pi/180 rad, with rad defined according to the 1960 SI units.
electron volt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/electronvolt
A unit of energy equal to the amount of kinetic energy acquired by an electron as it accelerates through a 1 volt potential difference in a vacuum using the 1967 SI units.
hour (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/hour
A unit of time equal to 60 minutes, or 3600 seconds, using the 1967 base SI units.
minute (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/minute
A unit of time that is equal to 60 seconds, using the 1967 base SI units.
parsec (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/parsec
The distance at which 1 astronomical unit subtends an angle of 1 arcsecond using the definition of the astronomical unit and arcsecond appearing in the International System of Units (SI), 1st ed. (1970)
tonne (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/tonne
A unit of mass defined as 1000 kg, with kilogram defined according to the 1960 SI units.
temporary
ångström (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/angstrom
A length equal to 10⁻¹⁰ meter, with meter defined according to the 1960 SI base units.
are (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/are
A unit of area equal to 100 square meters (10² m²), with meter defined according to the 1960 SI base units.
bar (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/bar
A unit of pressure equal to 10⁵ N/m using the 1967 base SI units.
barn (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/barn
A unit of area used in nuclear physics to express cross sections equal to 100 fm², with meter defined according to the 1960 SI units.
gal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/gal
A unit of acceleration equal to 1 centimeter per second squared (1 cm/s²), defined according to the 1967 SI units.
hectare (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/hectare
A unit of area equal to 1000 square meters (1 hm²), with meter defined according to the 1960 SI base unit.
knot (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/knot
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 1967 SI units.
nautical mile (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/nauticalmile
A unit of length primarily used in navigation defined as 1852 m using the 1960 SI meter.
radiation unit (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/radiationunit
A unit used to express the absorbed dose of ionizing radiation defined as 10⁻² J/kg using the 1967 SI units.
roentgen (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/roentgen
A unit used to express the exposure of ionizing radiation defined as 2.58 x 10⁻⁴ C/kg using the 1967 SI units.
1971
base
mole (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1971/base/mole
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.
named
pascal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1971/named/pascal
A derived SI unit for pressure and stress equal to kg·m⁻¹·s⁻² using the 1967 SI base units, defined at the 14th CGPM Meeting (1971).
siemens (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1971/named/siemens
A derived SI unit for electrical conductance equal to kg⁻¹·m⁻²·s³·A² using the 1967 SI base units, defined at the 14th CGPM Meeting (1971).
1975
named
becquerel (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1975/named/becquerel
A derived SI unit for radioactivity, defined as s⁻¹ using the 1967 SI second, defined at the 15th CGPM Meeting in 1975.
gray (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1975/named/gray
A derived SI unit for absorbed dose of ionizing radiation equal to m²·s⁻² using the 1967 base SI units at the 15th CGPM Meeting in 1975.
1979
base
candela (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1979/base/candela
The SI base unit of luminous intensity in a given direction defined from the luminous intensity of monochromatic radiation at a specific frequency and radiant intensity at the 16th CGPM Meeting in 1979.
named
lumen (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1979/named/lumen
A derived SI unit for luminous flux equal to cd·sr using the 1983 SI units.
lux (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1979/named/lux
A derived SI unit for illuminance equal to cd⋅sr⋅m⁻² in the 1979 SI units.
sievert (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1979/named/sievert
A derived SI unit for equivalent dose of ionizing radiation equal to J·kg⁻¹ (m²·s⁻²) using the 1967 SI base units, defined at the 16th CGPM meeting in 1979.
1981
roentgen equivalent man (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1981/temporary/rem
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 10⁻² Sv using the 1967 SI units.
1983
accepted
electron volt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/accepted/electronvolt
A unit of energy equal to the amount of kinetic energy acquired by an electron as it accelerates through a 1 volt potential difference in a vacuum using the 1967 SI units.
litre (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/accepted/litre
The litre, or liter is a unit of volume equal to a cubic decimetre (1 dm³) implicitly redefined via the redefinition of the meter at the 17th CGPM Meeting in 1983, resolution 1.
base
ampere (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/base/ampere
The SI base unit of electric current defined from the force between parallel wires carrying an electric current at the 41st CIPM meeting (1946) and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967 and the redefinition of the metre at the 17th CGPM Meeting in 1983.
candela (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/base/candela
The candela is the SI base unit of luminous intensity in a given direction defined from the luminous intensity of monochromatic radiation at a specific frequency and radiant intensity at the 16th CGPM Meeting in 1979; implicitly redefined via the redefinition of the metre at the 17th CGPM Meeting in 1983.
metre (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/base/metre
The metre, or meter, is the SI base unit of length defined via the distance light travels in vacuum during a fixed time interval after the redefinition at the 17th CGPM Meeting in 1983.
named
coulomb (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/coulomb
A derived SI unit for electric charge equal to s·A in the 1983 SI base units.
farad (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/farad
A derived SI unit for electrical capacitance equal to kg⁻¹·m⁻²·s⁴·A² in the 1967 SI units.
gray (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/gray
A derived SI unit for absorbed dose of ionizing radiation equal to m²·s⁻² using the 1983 SI units.
henry (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/henry
A derived SI unit for inductance equal to kg·m²·s⁻²·A⁻² in the 1983 SI units.
joule (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/joule
A derived SI unit for energy, work, and heat equal to kg·m²·s⁻² in the 1983 SI units.
lumen (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/lumen
A derived SI unit for luminous flux equal to cd·sr using the 1983 SI units.
lux (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/lux
A derived SI unit for illuminance equal to cd⋅sr⋅m⁻² in 1983 SI units.
newton (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/newton
The newton is a derived SI unit for force and weight equal to kg·m·s⁻² in 1983 SI units.
ohm (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/ohm
A derived SI unit for electrical resistance equal to kg·m²·s⁻³·A⁻² in the 1983 SI units.
pascal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/pascal
A derived SI unit for pressure and stress equal to kg·m⁻¹·s⁻² using the 1983 SI units.
siemens (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/siemens
A derived SI unit for electrical conductance equal to kg⁻¹·m⁻²·s³·A² using the 1983 SI base units.
sievert (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/sievert
A derived SI unit for equivalent dose of ionizing radiation equal to m²·s⁻² using the 1983 SI base units.
tesla (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/tesla
A derived SI unit for magnetic flux density equal to kg·s⁻²·A⁻¹ in the 1983 SI units.
volt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/volt
A derived SI unit for electric potential, voltage, and electromotive force equal to kg·m²·s⁻³·A⁻¹ in the 1983 SI units.
watt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/watt
A derived SI unit for power and radiant flux equal to kg·m²·s⁻³ in the 1983 SI units.
weber (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/named/weber
A derived SI unit for magnetic flux equal to kg·m²·s⁻³·A⁻¹ in the 1983 SI units.
temporary
ångström (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/angstrom
A length equal to 10⁻¹⁰ meter, with meter defined according to the 1983 SI base units.
are (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/are
A unit of area equal to 100 square meters (10² m²), with meter defined according to the 1983 SI units.
bar (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/bar
A unit of pressure equal to 10⁵ N/m using the 1983 base SI units.
barn (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/barn
A unit of area used in nuclear physics to express cross sections equal to 100 fm², with meter defined according to the 1983 SI units.
gal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/gal
A unit of acceleration equal to 1 centimeter per second squared (1 cm/s²), defined according to the 1983 SI units.
hectare (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/hectare
A unit of area equal to 1000 square meters (1 hm²), with meter defined according to the 1983 SI base unit.
knot (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/knot
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 1983 SI units.
nautical mile (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/nauticalmile
A unit of length primarily used in navigation defined as 1852 m using the 1983 SI meter.
radiation unit (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/radiationunit
A unit used to express the absorbed dose of ionizing radiation defined as 10⁻² J/kg using the 1983 SI units.
roentgen (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1983/temporary/roentgen
A unit used to express the exposure of ionizing radiation defined as 2.58 x 10⁻⁴ C/kg using the 1983 SI units.
1998
dalton (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1998/accepted/dalton
A unit of mass defined as 1/12 of the mass of a free carbon 12 atom, at rest and in its ground state.
1999
katal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/1999/named/katal
A derived SI unit for catalytic activity, defined as mol·s⁻¹ defined at the 21st CGPM meeting in 1999.
2019
accepted
astronomical unit (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/accepted/astronomicalunit
A unit defined as exactly 149597870700 meters which is meant to represent the mean distance between the Earth and the Sun using the SI 1983 meter.
electron volt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/accepted/electronvolt
A unit of energy equal to the amount of kinetic energy acquired by an electron as it accelerates through a 1 volt potential difference in a vacuum using the 2019 SI units.
tonne (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/accepted/tonne
A unit of mass defined as 1000 kg, with kilogram defined according to the 2019 SI units.
base
ampere (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/base/ampere
The SI base unit of electric current defined by fixing the value of the elementary charge as defined at the 26th CGPM Meeting (2018) and adopted into SI in 2019.
candela (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/base/candela
The SI base unit of luminous intensity in a given direction defined by fixing the value of the luminous efficacy of radiation of a specific frequency precisely matching the definition at the 16th CGPM Meeting in 1979 using the 2019 SI units.
kelvin (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/base/kelvin
The SI base unit of thermodynamic temperature defined by fixing the value of the Boltzmann constant as defined at the 26th CGPM Meeting (2018) and adopted into SI in 2019.
kilogram (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/base/kilogram
The SI base unit of mass defined by fixing the value of the Planck constant as defined at the 26th CGPM Meeting (2018) and adopted into SI in 2019.
mole (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/base/mole
The SI base unit of amount of substance defined by fixing the value of Avogadro constant as defined at the 26th CGPM Meeting (2018) and adopted into SI in 2019.
named
coulomb (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/coulomb
A derived SI unit for electric charge equal to s·A in the 1983 SI base units.
degree Celsius (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/degcelsius
A derived SI unit of temperature, defined as kelvin offset with +273.15 in the 2019 SI units.
farad (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/farad
A derived SI unit for electrical capacitance equal to kg⁻¹·m⁻²·s⁴·A² in the 2019 SI units.
henry (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/henry
A derived SI unit for inductance equal to kg·m²·s⁻²·A⁻² in the 1983 SI units.
joule (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/joule
A derived SI unit for energy, work, and heat equal to kg·m²·s⁻² in the 1983 SI units.
katal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/katal
A derived SI unit for catalytic activity, defined as mol·s⁻¹ using the 2019 SI units.
lumen (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/lumen
A derived SI unit for luminous flux equal to cd·sr using the 1983 SI units.
lux (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/lux
A derived SI unit for illuminance equal to cd⋅sr⋅m⁻² in 2019 SI units.
newton (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/newton
A derived SI unit for force and weight equal to kg·m·s⁻² in 2019 SI units.
ohm (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/ohm
A derived SI unit for electrical resistance equal to kg·m²·s⁻³·A⁻² in the 2019 SI units.
pascal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/pascal
A derived SI unit for pressure and stress equal to kg·m⁻¹·s⁻² using the 2019 SI units.
siemens (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/siemens
A derived SI unit for electrical conductance equal to kg⁻¹·m⁻²·s³·A² using the 2019 SI base units.
tesla (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/tesla
A derived SI unit for magnetic flux density equal to kg·s⁻²·A⁻¹ in the 2019 SI units.
volt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/volt
A derived SI unit for electric potential, voltage, and electromotive force equal to kg·m²·s⁻³·A⁻¹ in the 2019 SI units.
watt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/watt
A derived SI unit for power and radiant flux equal to kg·m²·s⁻³ in the 1983 SI units.
weber (unit) - https://schemas.optimade.org/defs/v1.2/units/si/2019/named/weber
A derived SI unit for magnetic flux equal to kg·m²·s⁻³·A⁻¹ in the 2019 SI units.
general
ampere (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/ampere
A unit of electric current defined according to the current, or one of the historical, definitions of the SI units.
ångström (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/angstrom
A unit of length equal to 10⁻¹⁰ meter, using the current, or one of the historical, definitions of the SI units.
arcminute (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/arcminute
A unit of plane and phase angle equal to 1/60 of a degree representing 1/21600 of a circle, equal to π/10800 rad, using the current, or one of the historical, definitions of the SI units.
arcsecond (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/arcsecond
A unit of plane and phase angle equal to 1/60 of an arcminute representing 1/1296000 of a circle, equal to π/648000 rad, using the current, or one of the historical, definitions of the SI units.
are (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/are
A unit of area equal to 100 square meters (10² m²) using the current, or one of the historical, definitions of the SI units.
astronomical unit (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/astronomicalunit
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).
standard atmosphere (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/atmosphere
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.
atomic mass unit (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/atomicmassunit
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).
bar (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/bar
A unit of pressure equal to 10⁵ N/m using the current, or one of the historical, definitions of the SI units.
barn (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/barn
A unit of area used in nuclear physics to express cross sections equal to 100 fm² using the current, or one of the historical, definitions of the SI units.
becquerel (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/becquerel
A unit for radioactivity, defined as s⁻¹ using the current, or one of the historical, definitions of the SI units.
candela (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/candela
A unit of luminous intensity in a given direction defined according to the current, or one of the historical, definitions of the SI units.
coulomb (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/coulomb
A unit for electric charge equal to s·A using the current, or one of the historical, definitions of the SI units.
curie (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/curie
A unit of activity with the value 3.7·10⁻¹⁰ s⁻¹ using the current, or one of the historical, definitions of the SI units.
dalton (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/dalton
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).
day (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/day
A unit of time equal to 86 400 seconds using the current, or one of the historical, definitions of the SI units.
degree Celsius (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/degcelsius
A unit of temperature, defined as kelvin offset with +273.15 using the current, or one of the historical, definitions of the SI units.
degree (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/degree
A unit of plane and phase angle representing 1/360 of a full circle, equal to π/180 rad using the current, or one of the historical, definitions of the SI units.
electron volt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/electronvolt
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).
farad (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/farad
A unit for electrical capacitance equal to kg⁻¹·m⁻²·s⁴·A² using the current, or one of the historical, definitions of the SI units.
gal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/gal
A unit of acceleration equal to 1 centimeter per second squared (1 cm/s²), using the current, or one of the historical, definitions of the SI units.
gray (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/gray
A unit for absorbed dose of ionizing radiation equal to m²·s⁻² using the current, or one of the historical, definitions of the SI units.
hectare (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/hectare
A unit of area equal to 1000 square meters (1 hm²), using the current, or one of the historical, definitions of the SI units.
henry (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/henry
A unit for inductance equal to kg·m²·s⁻²·A⁻² using the current, or one of the historical, definitions of the SI units.
hertz (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/hertz
A unit for frequency equal to s⁻¹ using the current, or one of the historical, definitions of the SI units.
hour (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/hour
A unit of time equal to 60 minutes, or 3600 seconds, using the current, or one of the historical, definitions of the SI units.
joule (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/joule
A derived SI unit for energy, work, and heat equal to kg·m²·s⁻² using the current, or one of the historical, definitions of the SI units.
katal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/katal
A derived SI unit for catalytic activity, defined as mol·s⁻¹ using the current, or one of the historical, definitions of the SI units.
kelvin (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/kelvin
A unit of thermodynamic temperature using the current, or one of the historical, definitions of the SI units.
kilogram (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/kilogram
A unit of mass using the current, or one of the historical, definitions of the SI units.
knot (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/knot
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.
litre (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/litre
The litre, or liter is a unit of volume equal to a cubic decimetre (1 dm³) using the current, or one of the historical, definitions of the SI units.
lumen (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/lumen
A derived SI unit for luminous flux equal to cd·sr using the current, or one of the historical, definitions of the SI units.
lux (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/lux
A derived SI unit for illuminance equal to cd⋅sr⋅m⁻² using the current, or one of the historical, definitions of the SI units.
metre (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/metre
The metre, or meter, is a unit of length using the current, or one of the historical, definitions of the SI units.
minute (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/minute
A unit of time that is equal to 60 seconds, using the current, or one of the historical, definitions of the SI units.
mole (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/mole
A unit of amount of substance using the current, or one of the historical, definitions of the SI units.
nautical mile (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/nauticalmile
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.
newton (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/newton
A unit for force and weight equal to kg·m·s⁻² using the current, or one of the historical, definitions of the SI units.
ohm (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/ohm
A unit for electrical resistance equal to kg·m²·s⁻³·A⁻² using the current, or one of the historical, definitions of the SI units.
parsec (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/parsec
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.
pascal (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/pascal
A unit for pressure and stress equal to kg·m⁻¹·s⁻² using the current, or one of the historical, definitions of the SI units.
radian (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/radian
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 4π radians using the current, or one of the historical, definitions of the SI units.
radiation unit (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/radiationunit
A unit used to express the absorbed dose of ionizing radiation defined as 10⁻² J/kg using the current, or one of the historical, definitions of the SI units.
roentgen equivalent man (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/rem
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 10⁻² Sv using the current, or one of the historical, definitions of the SI units.
roentgen (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/roentgen
A unit used to express the exposure of ionizing radiation defined as 2.58 x 10⁻⁴ C/kg using the current, or one of the historical, definitions of the SI units.
second (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/second
A unit of time using the current, or one of the historical, definitions of the SI units.
siemens (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/siemens
A unit for electrical conductance equal to kg⁻¹·m⁻²·s³·A² using the current, or one of the historical, definitions of the SI units.
sievert (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/sievert
A unit for equivalent dose of ionizing radiation equal to m²·s⁻² using the current, or one of the historical, definitions of the SI units.
steradian (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/steradian
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 4π steradians using the current, or one of the historical, definitions of the SI units.
tesla (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/tesla
A unit for magnetic flux density equal to kg·s⁻²·A⁻¹ using the current, or one of the historical, definitions of the SI units.
tonne (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/tonne
A unit of mass equal to 1000 kg using the current, or one of the historical, definitions of the SI units.
volt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/volt
A unit for electric potential, voltage, and electromotive force equal to kg·m²·s⁻³·A⁻¹ using the current, or one of the historical, definitions of the SI units.
watt (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/watt
A unit for power and radiant flux equal to kg·m²·s⁻³ using the current, or one of the historical, definitions of the SI units.
weber (unit) - https://schemas.optimade.org/defs/v1.2/units/si/general/weber
A unit for magnetic flux equal to kg·m²·s⁻³·A⁻¹ using the current, or one of the historical, definitions of the SI units.
unitsystems
optimade
OPTIMADE (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/optimade/optimade
A combination of SI and non-SI units in common use suitable for use with OPTIMADE.
si
SI 1970 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_1970
The SI unit system as represented in the 1st edition of the International System of Units.
SI 1973 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_1973
The SI unit system as represented in the 2nd edition of the International System of Units.
SI 1977 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_1977
The SI unit system as represented in the 3rd edition of the International System of Units.
SI 1981 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_1981
The SI unit system as represented in the 4th edition of the International System of Units.
SI 1985 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_1985
The SI unit system as represented in the 5th edition of the International System of Units.
SI 1991 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_1991
The SI unit system as represented in the 6th edition of the International System of Units.
SI 1998 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_1998
The SI unit system as represented in the 7th edition of the International System of Units.
SI 2006 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_2006
The SI unit system as represented in the 8th edition of the International System of Units.
SI 2019 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_2019
The SI 2019 unit system as represented in the 9th edition (v1.06) of the International System of Units.
SI accepted 2019 (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_accepted_2019
The SI 2019 unit system and units accepted to be used with the SI.
SI general (unitsystem) - https://schemas.optimade.org/defs/v1.2/unitsystems/si/si_general
The SI unit system, using current or historical definitions of the SI units.