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Add space_group_symmetry_operations_xyz and sub-definition for sym ops #4

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Original file line number Diff line number Diff line change
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$$schema: "https://schemas.optimade.org/meta/v1.2/optimade/property_definition"
$id: "https://schemas.optimade.org/defs/v1.2/properties/optimade/common/symmetry_operation_xyz"
title: "Symmetry operation"
x-optimade-type: "string"
x-optimade-definition:
label: "symmetry_operation_xyz_optimade_common"
kind: "property"
version: "1.2.0"
format: "1.2"
name: "symmetry_operation_xyz"
description: |-
A symmetry operation given as general position x, y, z coordinates in algebraic form.

**Requirements/Conventions:**

- The symmetry operation is described by a string that gives that symmetry operation in Jones' faithful representation (Bradley & Cracknell, 1972: pp. 35-37), adapted for computer string notation.
- The letters `x`, `y` and `z` that are typesetted with overbars in printed text represent coordinate values multiplied by -1 and are encoded as `-x`, `-y` and `-z`, respectively.
- The syntax of the strings representing symmetry operations MUST conform to regular expressions given in appendix `The Symmetry Operation String Regular Expressions`_.
x-optimade-unit: inapplicable
type:
- "string"
maxLength: 3
pattern: "^([-+]?[xyz]([-+][xyz])?([-+](1/2|[12]/3|[1-3]/4|[1-5]/6))?|[-+]?(1/2|[12]/3|[1-3]/4|[1-5]/6)([-+][xyz]([-+][xyz])?)?),([-+]?[xyz]([-+][xyz])?([-+](1/2|[12]/3|[1-3]/4|[1-5]/6))?|[-+]?(1/2|[12]/3|[1-3]/4|[1-5]/6)([-+][xyz]([-+][xyz])?)?),([-+]?[xyz]([-+][xyz])?([-+](1/2|[12]/3|[1-3]/4|[1-5]/6))?|[-+]?(1/2|[12]/3|[1-3]/4|[1-5]/6)([-+][xyz]([-+][xyz])?)?)$"
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Original file line number Diff line number Diff line change
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$$schema: "https://schemas.optimade.org/meta/v1.2/optimade/property_definition"
$id: "https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/space_group_symmetry_operations_xyz"
title: "Space group symmetry operations"
x-optimade-type: "list"
x-optimade-definition:
label: "space_group_symmetry_operations_xyz_optimade_structures"
kind: "property"
version: "1.2.0"
format: "1.2"
name: "space_group_symmetry_operations_xyz"
type:
- "array"
- "null"
description: |-
A list of symmetry operations given as general position x, y and z coordinates in algebraic form.

**Requirements/Conventions**:

- Each symmetry operation is described by a string that gives that symmetry operation in Jones' faithful representation (Bradley & Cracknell, 1972: pp. 35-37), adapted for computer string notation.
- The letters `x`, `y` and `z` that are typesetted with overbars in printed text represent coordinate values multiplied by -1 and are encoded as `-x`, `-y` and `-z`, respectively.
- The syntax of the strings representing symmetry operations MUST conform to regular expressions given in appendix `The Symmetry Operation String Regular Expressions`_.
- The interpretation of the strings MUST follow the conventions of the IUCr CIF core dictionary (IUCr, 2023).
- In particular, this property MUST explicitly provide all symmetry operations needed to generate all the atoms in the unit cell from the atoms in the asymmetric unit, for the setting used.
- This symmetry operation set MUST always include the `x,y,z` identity operation.
- The symmetry operations are to be applied to fractional atom coordinates.
- In case only Cartesian coordinates are available, these Cartesian coordinates must be converted to fractional coordinates before the application of the provided symmetry operations.
- If the symmetry operation list is present, it MUST be compatible with other space group specifications (e.g. the ITC space group number, the Hall symbol, the Hermann-Mauguin symbol) if these are present.

**Notes**:

- The list of space group symmetry operations applies to the whole periodic array of atoms and together with the lattice translations given in the :property:`lattice\_vectors` property provides the necessary information to reconstruct all atom site positions of the periodic material.
- Thus, the symmetry operations described in this property are only applicable to material models with at least one periodic dimension.
- This property is not meant to represent arbitrary symmetries of molecules, non-periodic (finite) collections of atoms or non-crystallographic symmetry.

**Bibliographic References**

- Bradley, C. J. and Cracknell, A. P. (1972) The Mathematical Theory of Symmetry in Solids. Oxford, Clarendon Press (paperback edition 2010) 745 p. ISBN `978-0-19-958258-7 <https://isbnsearch.org/isbn/9780199582587>`__.
- IUCr (2023) Core dictionary (coreCIF) version 2.4.5; data name `\_space\_group\_symop\_operation\_xyz`. Available from: https://www.iucr.org/__data/iucr/cifdic_html/1/cif_core.dic/Ispace_group_symop_operation_xyz.html [Accessed 2023-06-18T16:46+03:00].
examples:
- ["x,y,z", "-x,y,-z"]
- ["x,y,z", "-x,y,-z", "x+1/2,y+1/2,z", "-x+1/2,y+1/2,-z"]
x-optimade-unit: "unapplicable"