Hall symbol (property)

{
    "$id": "https://schemas.anyterial.se/defs/v0.1/properties/spacegroups/hall",
    "$schema": "https://schemas.optimade.org/meta/v1.3/optimade/property_definition.json",
    "title": "Hall symbol",
    "x-optimade-type": "string",
    "x-compatibility": [
        "https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/space_group_symbol_hall"
    ],
    "x-optimade-definition": {
        "kind": "property",
        "version": "0.1.0",
        "format": "1.3",
        "name": "hall",
        "label": "hall_spacegroups"
    },
    "type": [
        "string",
        "null"
    ],
    "description": "The Hall symbol for a crystallographic space-group setting.\n\nHall symbols encode the generators and origin choice of a space-group setting in a form intended to identify the setting unambiguously.\nThe normalized lookup-key form of this symbol, using lowercase letters and underscores in place of spaces, is provided by `hall_entry`.",
    "x-optimade-unit": "inapplicable",
    "examples": [
        "P 1",
        "C 2y"
    ]
}