This page documents an OPTIMADE Property Definition. See https://schemas.optimade.org/ for more information.
ID: https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/space_group_symbol_hermann_mauguin
Definition name: space_group_symbol_hermann_mauguin
Property name: Hermann-Mauguin space group symbol
Description: 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.
Type: string
Requirements/Conventions:
To encode as character strings, the following adaptations MUST be made when representing H-M symbols given in their typesetted form:
-2
);P 32
);P 21 21 2
);P 21/m
, not the P 21 / m
);Bibliographic References
Examples:
"C 2"
"P 21 21 21"
JSON definition:
{
"$id": "https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/space_group_symbol_hermann_mauguin",
"$schema": "https://schemas.optimade.org/meta/v1.2/optimade/property_definition.json",
"title": "Hermann-Mauguin space group symbol",
"x-optimade-type": "string",
"x-optimade-definition": {
"label": "space_group_symbol_hermann_mauguin_optimade_structures",
"kind": "property",
"version": "1.2.0",
"format": "1.2",
"name": "space_group_symbol_hermann_mauguin"
},
"type": [
"string",
"null"
],
"description": "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.\n\n**Requirements/Conventions**:\n\n- The H-M symbol SHOULD aim to convey the closest representation of the symmetry information that can be specified using the short format used in the International Tables for Crystallography vol. A (IUCr, 2005), Table 4.3.2.1 as described in the accompanying text.\n- The symbol MAY be a non-standard short H-M symbol.\n- The H-M symbol does not unambiguously communicate the axis, cell, and origin choice, and the given symbol SHOULD NOT be amended to convey this information.\n- To encode as character strings, the following adaptations MUST be made when representing H-M symbols given in their typesetted form:\n\n - the overbar above the numbers MUST be changed to the minus sign in front of the digit (e.g. `-2`);\n - subscripts that denote screw axes are written as digits immediately after the axis designator without a space (e.g. `P 32`);\n - the space group generators MUST be separated by a single space (e.g. `P 21 21 2`);\n - there MUST be no spaces in the space group generator designation (i.e. use `P 21/m`, not the `P 21 / m`);\n\n**Bibliographic References**\n\n- IUCr (2005). International Tables for Crystallography vol. A. Space-Group Symmetry. Ed. Theo Hahn. 5-th edition. Dordrecht, Springer.",
"examples": [
"C 2",
"P 21 21 21"
],
"x-optimade-unit": "unapplicable"
}