International
Tables for
Crystallography
Volume G
Definition and exchange of crystallographic data
Edited by J. R. Hester and B. McMahon

© International Union of Crystallography 2026
International Tables for Crystallography (2026). Vol. G. Early view chapter
https://doi.org/10.1107/97809553602060001011

Chapter 4.3 Multi-block CIF dictionary

Expanded view
View CIF syntax

Version 1.1.0 (2026-11-03)

The multi-block dictionary adds data names to the core dictionary which allow description of data spread over multiple data units (blocks). Under the default schema, all data names in Set categories must be single-valued in any given data block. If these Set categories are provided with one or more key data names, information in these categories spread over multiple data blocks can be combined together. When key data names are specified, all child data names in other categories should be specified at the same time, as well as data names that reference items in the given Set category. This dictionary redefines Set categories to include the new key data names, adds the key data-name definitions, and defines any linked and child data names.

Category tree view of data-item definitions

MODEL
CIF 
Data items in the MODEL category specify data for the crystal structure
postulated and modelled from the atomic coordinates derived and
refined from the diffraction information. The structural model is
described principally in terms of the geometry of the 'connected'
atom sites and the crystal symmetry in which they reside.

save_MODEL

    _definition.id                MODEL
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2026-06-17
    _description.text
;
    Data items in the MODEL category specify data for the crystal structure
    postulated and modelled from the atomic coordinates derived and
    refined from the diffraction information. The structural model is
    described principally in terms of the geometry of the 'connected'
    atom sites and the crystal symmetry in which they reside.
;
    _name.category_id             CIF_CORE_MULTIBLOCK_HEAD
    _name.object_id               MODEL
    _category_key.name            '_model.id'

save_
_model.id
CIF 
Arbitrary code identifying the model.

save_model.id

    _definition.id                '_model.id'
    _definition.update            2025-06-04
    _description.text
;
    Arbitrary code identifying the model.
;
    _name.category_id             model
    _name.object_id               id
    _type.purpose                 Key
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
_model.structure_id
CIF 
A code identifying the structure to which the model was applied.

save_model.structure_id

    _definition.id                '_model.structure_id'
    _definition.update            2025-06-04
    _description.text
;
    A code identifying the structure to which the model was applied.
;
    _name.category_id             model
    _name.object_id               structure_id
    _name.linked_item_id          '_structure.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
GEOM
CIF 
Data items in the GEOM category describe aspects of the overall
geometry of the structural model as derived from the atomic sites.
The detailed geometry is expressed in terms of the interatomic
angles (GEOM_ANGLE data), covalent bond distances (GEOM_BOND
data), contact distances (GEOM_CONTACT data), hydrogen bonds
(GEOM_HBOND data) and torsion geometry (GEOM_TORSION data).
Geometry data are usually redundant, in that they can be
calculated from other more fundamental quantities in the data
block. However, they serve the dual purposes of providing a check
on the correctness of both sets of data and of enabling the most
important geometric data to be identified for publication by
setting the appropriate publication flag.

save_GEOM

    _definition.id                GEOM
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2025-06-04
    _description.text
;
    Data items in the GEOM category describe aspects of the overall
    geometry of the structural model as derived from the atomic sites.
    The detailed geometry is expressed in terms of the interatomic
    angles (GEOM_ANGLE data), covalent bond distances (GEOM_BOND
    data), contact distances (GEOM_CONTACT data), hydrogen bonds
    (GEOM_HBOND data) and torsion geometry (GEOM_TORSION data).
    Geometry data are usually redundant, in that they can be
    calculated from other more fundamental quantities in the data
    block. However, they serve the dual purposes of providing a check
    on the correctness of both sets of data and of enabling the most
    important geometric data to be identified for publication by
    setting the appropriate publication flag.
;
    _name.category_id             MODEL
    _name.object_id               GEOM
    _category_key.name            '_geom.model_id'

save_
_geom.model_id
CIF 
A code identifying the model to which the geometry relates.

save_geom.model_id

    _definition.id                '_geom.model_id'
    _definition.update            2025-06-04
    _description.text
;
    A code identifying the model to which the geometry relates.
;
    _name.category_id             geom
    _name.object_id               model_id
    _name.linked_item_id          '_model.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
GEOM_ANGLE
CIF 
Data items in the GEOM_ANGLE category specify the geometry
angles in the structural model as derived from the atomic sites.

save_GEOM_ANGLE

    _definition.id                GEOM_ANGLE
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2025-06-04
    _description.text
;
    Data items in the GEOM_ANGLE category specify the geometry
    angles in the structural model as derived from the atomic sites.
;
    _name.category_id             GEOM
    _name.object_id               GEOM_ANGLE

    loop_
      _category_key.name
         '_geom_angle.atom_site_label_1'
         '_geom_angle.atom_site_label_2'
         '_geom_angle.atom_site_label_3'
         '_geom_angle.model_id'
         '_geom_angle.site_symmetry_1'
         '_geom_angle.site_symmetry_2'
         '_geom_angle.site_symmetry_3'

save_
_geom_angle.model_id
CIF 
A code identifying the model to which the geometry relates.

save_geom_angle.model_id

    _definition.id                '_geom_angle.model_id'
    _definition.update            2025-06-04
    _description.text
;
    A code identifying the model to which the geometry relates.
;
    _name.category_id             geom_angle
    _name.object_id               model_id
    _name.linked_item_id          '_model.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
GEOM_BOND
CIF 
Data items in the GEOM_BOND category specify the geometry bonds in the
structural model as derived from the atomic sites.

save_GEOM_BOND

    _definition.id                GEOM_BOND
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2025-06-04
    _description.text
;
    Data items in the GEOM_BOND category specify the geometry bonds in the
    structural model as derived from the atomic sites.
;
    _name.category_id             GEOM
    _name.object_id               GEOM_BOND

    loop_
      _category_key.name
         '_geom_bond.atom_site_label_1'
         '_geom_bond.atom_site_label_2'
         '_geom_bond.model_id'
         '_geom_bond.site_symmetry_1'
         '_geom_bond.site_symmetry_2'

save_
_geom_bond.model_id
CIF 
A code identifying the model to which the geometry relates.

save_geom_bond.model_id

    _definition.id                '_geom_bond.model_id'
    _definition.update            2025-06-04
    _description.text
;
    A code identifying the model to which the geometry relates.
;
    _name.category_id             geom_bond
    _name.object_id               model_id
    _name.linked_item_id          '_model.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
GEOM_CONTACT
CIF 
Data items in the GEOM_CONTACT category specify the interatomic
contact distances in the structural model.

save_GEOM_CONTACT

    _definition.id                GEOM_CONTACT
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2025-06-04
    _description.text
;
    Data items in the GEOM_CONTACT category specify the interatomic
    contact distances in the structural model.
;
    _name.category_id             GEOM
    _name.object_id               GEOM_CONTACT

    loop_
      _category_key.name
         '_geom_contact.atom_site_label_1'
         '_geom_contact.atom_site_label_2'
         '_geom_contact.model_id'
         '_geom_contact.site_symmetry_1'
         '_geom_contact.site_symmetry_2'

save_
_geom_contact.model_id
CIF 
A code identifying the model to which the geometry relates.

save_geom_contact.model_id

    _definition.id                '_geom_contact.model_id'
    _definition.update            2025-06-04
    _description.text
;
    A code identifying the model to which the geometry relates.
;
    _name.category_id             geom_contact
    _name.object_id               model_id
    _name.linked_item_id          '_model.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
GEOM_HBOND
CIF 
Data items in the GEOM_HBOND category specify the hydrogen bond
The CATEGORY of data items used to specify the hydrogen bond
distances in the structural model as derived from atomic sites.

save_GEOM_HBOND

    _definition.id                GEOM_HBOND
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2025-06-04
    _description.text
;
    Data items in the GEOM_HBOND category specify the hydrogen bond
    The CATEGORY of data items used to specify the hydrogen bond
    distances in the structural model as derived from atomic sites.
;
    _name.category_id             GEOM
    _name.object_id               GEOM_HBOND

    loop_
      _category_key.name
         '_geom_hbond.atom_site_label_D'
         '_geom_hbond.atom_site_label_H'
         '_geom_hbond.atom_site_label_A'
         '_geom_hbond.model_id'
         '_geom_hbond.site_symmetry_D'
         '_geom_hbond.site_symmetry_H'
         '_geom_hbond.site_symmetry_A'

save_
_geom_hbond.model_id
CIF 
A code identifying the model to which the geometry relates.

save_geom_hbond.model_id

    _definition.id                '_geom_hbond.model_id'
    _definition.update            2025-06-04
    _description.text
;
    A code identifying the model to which the geometry relates.
;
    _name.category_id             geom_hbond
    _name.object_id               model_id
    _name.linked_item_id          '_model.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
GEOM_TORSION
CIF 
Data items in the GEOM_TORSION category specify the torsion angles in the
structural model as derived from the atomic sites.

save_GEOM_TORSION

    _definition.id                GEOM_TORSION
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2025-06-04
    _description.text
;
    Data items in the GEOM_TORSION category specify the torsion angles in the
    structural model as derived from the atomic sites.
;
    _name.category_id             GEOM
    _name.object_id               GEOM_TORSION

    loop_
      _category_key.name
         '_geom_torsion.atom_site_label_1'
         '_geom_torsion.atom_site_label_2'
         '_geom_torsion.atom_site_label_3'
         '_geom_torsion.atom_site_label_4'
         '_geom_torsion.model_id'
         '_geom_torsion.site_symmetry_1'
         '_geom_torsion.site_symmetry_2'
         '_geom_torsion.site_symmetry_3'
         '_geom_torsion.site_symmetry_4'

save_
_geom_torsion.model_id
CIF 
A code identifying the model to which the geometry relates.

save_geom_torsion.model_id

    _definition.id                '_geom_torsion.model_id'
    _definition.update            2025-06-04
    _description.text
;
    A code identifying the model to which the geometry relates.
;
    _name.category_id             geom_torsion
    _name.object_id               model_id
    _name.linked_item_id          '_model.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
MODEL_SITE
CIF 
Data items in the MODEL_SITE category are used to describe
atomic sites and connections in the proposed atomic model.

save_MODEL_SITE

    _definition.id                MODEL_SITE
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2025-06-04
    _description.text
;
    Data items in the MODEL_SITE category are used to describe
    atomic sites and connections in the proposed atomic model.
;
    _name.category_id             MODEL
    _name.object_id               MODEL_SITE

    loop_
      _category_key.name
         '_model_site.label'
         '_model_site.model_id'
         '_model_site.symop'

save_
_model_site.model_id
CIF 
A code identifying the model to which the model site belongs.

save_model_site.model_id

    _definition.id                '_model_site.model_id'
    _definition.update            2025-06-04
    _description.text
;
    A code identifying the model to which the model site belongs.
;
    _name.category_id             model_site
    _name.object_id               model_id
    _name.linked_item_id          '_model.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
STRUCTURE
CIF 
A category for collecting information about a crystallographic structure.

save_STRUCTURE

    _definition.id                STRUCTURE
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2026-06-17
    _description.text
;
    A category for collecting information about a crystallographic structure.
;
    _name.category_id             CIF_CORE_MULTIBLOCK_HEAD
    _name.object_id               STRUCTURE
    _category_key.name            '_structure.id'

save_
_structure.diffrn_id
CIF 
A code which identifies the diffraction conditions under which the data for
this structure were collected.

save_structure.diffrn_id

    _definition.id                '_structure.diffrn_id'
    _definition.update            2023-01-17
    _description.text
;
    A code which identifies the diffraction conditions under which the data for
    this structure were collected.
;
    _name.category_id             structure
    _name.object_id               diffrn_id
    _name.linked_item_id          '_diffrn.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
_structure.id
CIF 
Unique identifier for a structure.

save_structure.id

    _definition.id                '_structure.id'
    _definition.update            2023-10-16
    _description.text
;
    Unique identifier for a structure.
;
    _name.category_id             structure
    _name.object_id               id
    _type.purpose                 Key
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
_structure.space_group_id
CIF 
A code which identifies the space group associated with the structure.

save_structure.space_group_id

    _definition.id                '_structure.space_group_id'
    _definition.update            2023-01-17
    _description.text
;
    A code which identifies the space group associated with the structure.
;
    _name.category_id             structure
    _name.object_id               space_group_id
    _name.linked_item_id          '_space_group.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
ATOM_SITE
CIF 
Data items in the ATOM_SITE category record details about
the atom sites in a crystal structure, such as the positional
coordinates and atomic displacement parameters.

Examples:
_structure.id  STR_1
         loop_
           _atom_site.label
           _atom_site.occupancy
           _atom_site.disorder_assembly
           _atom_site.disorder_group
            C1     1      .     .
            H11A   .5     M     1
            H12A   .5     M     1
            H13A   .5     M     1
            H11B   .5     M     2
            H12B   .5     M     2
            H13B   .5     M     2

_structure.id  STR_I
         loop_
           _atom_site.label
           _atom_site.type_symbol
           _atom_site.fract_x
           _atom_site.fract_y
           _atom_site.fract_z
           _atom_site.occupancy
           _atom_site.disorder_assembly
           _atom_site.disorder_group
            Cu1 Cu 0.78443(2) 0.88297(4) 0.37825(2)  1       . .
            Co1 Co 0.77504(2) 0.66957(4) 0.54249(2)  0.78(3) A 1
            Mn1 Mn 0.77504(2) 0.66957(4) 0.54249(2)  0.22(3) A 2
            O1   O 0.85532(9) 0.95747(19) 0.28965(9) 1       . .
            O2   O 0.84868(9) 0.94662(19) 0.14953(8) 1       . .
            # ...

save_ATOM_SITE

    _definition.id                ATOM_SITE
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2023-10-16
    _description.text
;
    Data items in the ATOM_SITE category record details about
    the atom sites in a crystal structure, such as the positional
    coordinates and atomic displacement parameters.
;
    _name.category_id             ATOM
    _name.object_id               ATOM_SITE

    loop_
      _category_key.name
         '_atom_site.label'
         '_atom_site.structure_id'

    loop_
      _description_example.case
      _description_example.detail
;
         _structure.id  STR_1
         loop_
           _atom_site.label
           _atom_site.occupancy
           _atom_site.disorder_assembly
           _atom_site.disorder_group
            C1     1      .     .
            H11A   .5     M     1
            H12A   .5     M     1
            H13A   .5     M     1
            H11B   .5     M     2
            H12B   .5     M     2
            H13B   .5     M     2
;
;
         A hypothetical example of a positional disorder description for the
         structure designated "STR_1". Disorder assembly 'M' describes a
         methyl group with two alternative configurations '1' and '2':

                            H11B    H11A      H13B
                              .      |      .
                                .    |    .
                                  .  |  .
                                     C1 --------C2---
                                   / .  \
                                 /   .    \
                               /     .      \
                            H12A    H12B    H13A
;
;
         _structure.id  STR_I
         loop_
           _atom_site.label
           _atom_site.type_symbol
           _atom_site.fract_x
           _atom_site.fract_y
           _atom_site.fract_z
           _atom_site.occupancy
           _atom_site.disorder_assembly
           _atom_site.disorder_group
            Cu1 Cu 0.78443(2) 0.88297(4) 0.37825(2)  1       . .
            Co1 Co 0.77504(2) 0.66957(4) 0.54249(2)  0.78(3) A 1
            Mn1 Mn 0.77504(2) 0.66957(4) 0.54249(2)  0.22(3) A 2
            O1   O 0.85532(9) 0.95747(19) 0.28965(9) 1       . .
            O2   O 0.84868(9) 0.94662(19) 0.14953(8) 1       . .
            # ...
;
;
         An example of a compositional disorder description for the
         structure designated "STR_I". Disorder assembly 'A' describes
         a site that is simultaneously occupied by Co and Mn atoms which
         are assigned to disorder group '1' and disorder group '2',
         respectively.

         Example based on data from:
             Li, A. et al. (2021). Dalton Trans. 50, 681-688.
             https://doi.org/10.1039/d0dt03269g
;

save_
_atom_site.structure_id
CIF 
A code identifying the structure to which this atom site belongs.

save_atom_site.structure_id

    _definition.id                '_atom_site.structure_id'
    _definition.update            2023-10-16
    _description.text
;
    A code identifying the structure to which this atom site belongs.
;
    _name.category_id             atom_site
    _name.object_id               structure_id
    _name.linked_item_id          '_structure.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
ATOM_SITE_ANISO
CIF 
Data items in the ATOM_SITE_ANISO category are used to describe the
anisotropic atomic displacement parameters of the atomic sites in a
crystal structure.

save_ATOM_SITE_ANISO

    _definition.id                ATOM_SITE_ANISO
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2023-10-16
    _description.text
;
    Data items in the ATOM_SITE_ANISO category are used to describe the
    anisotropic atomic displacement parameters of the atomic sites in a
    crystal structure.
;
    _name.category_id             ATOM_SITE
    _name.object_id               ATOM_SITE_ANISO

    loop_
      _category_key.name
         '_atom_site_aniso.label'
         '_atom_site_aniso.structure_id'

save_
_atom_site_aniso.structure_id
CIF 
A code identifying the structure to which this atom site belongs.

save_atom_site_aniso.structure_id

    _definition.id                '_atom_site_aniso.structure_id'
    _definition.update            2023-10-16
    _description.text
;
    A code identifying the structure to which this atom site belongs.
;
    _name.category_id             atom_site_aniso
    _name.object_id               structure_id
    _name.linked_item_id          '_atom_site.structure_id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
ATOM_SITES
CIF 
Data items in the ATOM_SITES category record details common
to all atom sites, such as general structure solution strategy
and coordinate transformations.

save_ATOM_SITES

    _definition.id                ATOM_SITES
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2026-06-15
    _description.text
;
    Data items in the ATOM_SITES category record details common
    to all atom sites, such as general structure solution strategy
    and coordinate transformations.
;
    _name.category_id             ATOM
    _name.object_id               ATOM_SITES
    _category_key.name            '_atom_sites.structure_id'

save_
_atom_sites.structure_id
CIF 
A code identifying the crystallographic structure associated with
this description of the atom sites.

save_atom_sites.structure_id

    _definition.id                '_atom_sites.structure_id'
    _definition.update            2026-06-15
    _description.text
;
    A code identifying the crystallographic structure associated with
    this description of the atom sites.
;
    _name.category_id             atom_sites
    _name.object_id               structure_id
    _name.linked_item_id          '_structure.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
ATOM_SITES_CARTN_TRANSFORM
CIF 
The category of data items which describe the matrix elements
used to transform fractional coordinates into Cartesian coordinates
of all atom sites in a crystal structure.

save_ATOM_SITES_CARTN_TRANSFORM

    _definition.id                ATOM_SITES_CARTN_TRANSFORM
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2026-06-15
    _description.text
;
    The category of data items which describe the matrix elements
    used to transform fractional coordinates into Cartesian coordinates
    of all atom sites in a crystal structure.
;
    _name.category_id             ATOM_SITES
    _name.object_id               ATOM_SITES_CARTN_TRANSFORM
    _category_key.name            '_atom_sites_Cartn_transform.structure_id'

save_
_atom_sites_Cartn_transform.structure_id
CIF 
A code identifying the crystallographic structure associated with this
Cartesian coordinate transform applied to the atom sites.

save_atom_sites_cartn_transform.structure_id

    _definition.id                '_atom_sites_Cartn_transform.structure_id'
    _definition.update            2026-06-15
    _description.text
;
    A code identifying the crystallographic structure associated with this
    Cartesian coordinate transform applied to the atom sites.
;
    _name.category_id             atom_sites_Cartn_transform
    _name.object_id               structure_id
    _name.linked_item_id          '_structure.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
ATOM_SITES_FRACT_TRANSFORM
CIF 
The category of data items which describe the matrix elements
used to transform Cartesian coordinates into fractional coordinates
of all atom sites in a crystal structure.

save_ATOM_SITES_FRACT_TRANSFORM

    _definition.id                ATOM_SITES_FRACT_TRANSFORM
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2026-06-15
    _description.text
;
    The category of data items which describe the matrix elements
    used to transform Cartesian coordinates into fractional coordinates
    of all atom sites in a crystal structure.
;
    _name.category_id             ATOM_SITES
    _name.object_id               ATOM_SITES_FRACT_TRANSFORM
    _category_key.name            '_atom_sites_fract_transform.structure_id'

save_
_atom_sites_fract_transform.structure_id
CIF 
A code identifying the crystallographic structure associated with this
fractional coordinate transform applied to the atom sites.

save_atom_sites_fract_transform.structure_id

    _definition.id                '_atom_sites_fract_transform.structure_id'
    _definition.update            2026-06-15
    _description.text
;
    A code identifying the crystallographic structure associated with this
    fractional coordinate transform applied to the atom sites.
;
    _name.category_id             atom_sites_fract_transform
    _name.object_id               structure_id
    _name.linked_item_id          '_structure.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
CELL
CIF 
Data items in the CELL category record details about the
crystal unit-cell parameters.

save_CELL

    _definition.id                CELL
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2023-03-02
    _description.text
;
    Data items in the CELL category record details about the
    crystal unit-cell parameters.
;
    _name.category_id             DIFFRN
    _name.object_id               CELL
    _category_key.name            '_cell.structure_id'

save_
_cell.structure_id
CIF 
A code identifying the crystallographic structure associated with this cell
description.

save_cell.structure_id

    _definition.id                '_cell.structure_id'
    _definition.update            2024-02-05
    _description.text
;
    A code identifying the crystallographic structure associated with this cell
    description.
;
    _name.category_id             cell
    _name.object_id               structure_id
    _name.linked_item_id          '_structure.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
CELL_MEASUREMENT
CIF 
Data items in the CELL_MEASUREMENT category are used to describe the
measurement of the crystallographic unit-cell parameters.

save_CELL_MEASUREMENT

    _definition.id                CELL_MEASUREMENT
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2022-05-25
    _description.text
;
    Data items in the CELL_MEASUREMENT category are used to describe the
    measurement of the crystallographic unit-cell parameters.
;
    _name.category_id             CELL
    _name.object_id               CELL_MEASUREMENT
    _category_key.name            '_cell_measurement.structure_id'

save_
_cell_measurement.condition_id
CIF 
A pointer to the diffraction conditions used for cell measurement,
where different from the diffraction conditions used for data
collection.

save_cell_measurement.condition_id

    _definition.id                '_cell_measurement.condition_id'
    _definition.update            2023-02-01
    _description.text
;
    A pointer to the diffraction conditions used for cell measurement,
    where different from the diffraction conditions used for data
    collection.
;
    _name.category_id             cell_measurement
    _name.object_id               condition_id
    _name.linked_item_id          '_diffrn.id'
    _type.purpose                 Link
    _type.source                  Related
    _type.container               Single
    _type.contents                Word
    _method.purpose               Definition
    _method.expression
;
    _enumeration.default = _cell_measurement.diffrn_id
;

save_
_cell_measurement.diffrn_id
CIF 
A pointer to the diffraction experiment to which these properties
of the cell measurement apply.

save_cell_measurement.diffrn_id

    _definition.id                '_cell_measurement.diffrn_id'
    _definition.update            2023-10-26
    _description.text
;
    A pointer to the diffraction experiment to which these properties
    of the cell measurement apply.
;
    _name.category_id             cell_measurement
    _name.object_id               diffrn_id
    _name.linked_item_id          '_diffrn.id'
    _type.purpose                 Link
    _type.source                  Related
    _type.container               Single
    _type.contents                Word

save_
_cell_measurement.structure_id
CIF 
A code identifying the structure to which the cell being measured belongs.

save_cell_measurement.structure_id

    _definition.id                '_cell_measurement.structure_id'
    _definition.update            2024-02-05
    _description.text
;
    A code identifying the structure to which the cell being measured belongs.
;
    _name.category_id             cell_measurement
    _name.object_id               structure_id
    _name.linked_item_id          '_structure.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
CELL_MEASUREMENT_REFLN
CIF 
Data items in the CELL_MEASUREMENT_REFLN category record
details about the reflections used in the determination of the
crystallographic cell parameters.

save_CELL_MEASUREMENT_REFLN

    _definition.id                CELL_MEASUREMENT_REFLN
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2023-10-16
    _description.text
;
    Data items in the CELL_MEASUREMENT_REFLN category record
    details about the reflections used in the determination of the
    crystallographic cell parameters.
;
    _name.category_id             CELL_MEASUREMENT
    _name.object_id               CELL_MEASUREMENT_REFLN

    loop_
      _category_key.name
         '_cell_measurement_refln.index_h'
         '_cell_measurement_refln.index_k'
         '_cell_measurement_refln.index_l'
         '_cell_measurement_refln.structure_id'

save_
_cell_measurement_refln.structure_id
CIF 
A code identifying the structure for which the reflections were measured.

save_cell_measurement_refln.structure_id

    _definition.id                '_cell_measurement_refln.structure_id'
    _definition.update            2023-10-16
    _description.text
;
    A code identifying the structure for which the reflections were measured.
;
    _name.category_id             cell_measurement_refln
    _name.object_id               structure_id
    _name.linked_item_id          '_structure.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
DIFFRN
CIF 
Data items in the DIFFRN category record details about the
intensity measurements.

save_DIFFRN

    _definition.id                DIFFRN
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2022-05-09
    _description.text
;
    Data items in the DIFFRN category record details about the
    intensity measurements.
;
    _name.category_id             DIFFRACTION
    _name.object_id               DIFFRN
    _category_key.name            '_diffrn.id'

save_
_diffrn.crystal_id
CIF 
Identifier for the crystal from which diffraction data were
collected. This is a pointer to _exptl_crystal.id.

save_diffrn.crystal_id

    _definition.id                '_diffrn.crystal_id'
    _definition.update            2022-05-09
    _description.text
;
    Identifier for the crystal from which diffraction data were
    collected. This is a pointer to _exptl_crystal.id.
;
    _name.category_id             diffrn
    _name.object_id               crystal_id
    _name.linked_item_id          '_exptl_crystal.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
_diffrn.diffrn_measurement_id
CIF 
Identifies the particular combination of sample mounting, positioning
and measurement strategy used to collect the diffraction data. This is
a pointer to _diffrn_measurement.id.

save_diffrn.diffrn_measurement_id

    _definition.id                '_diffrn.diffrn_measurement_id'
    _definition.update            2026-04-22
    _description.text
;
    Identifies the particular combination of sample mounting, positioning
    and measurement strategy used to collect the diffraction data. This is
    a pointer to _diffrn_measurement.id.
;
    _name.category_id             diffrn
    _name.object_id               diffrn_measurement_id
    _name.linked_item_id          '_diffrn_measurement.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
_diffrn.diffrn_radiation_id
CIF 
Identifies the characteristics of the radiation source
for the diffraction data. This is a pointer to
_diffrn_radiation.id.

save_diffrn.diffrn_radiation_id

    _definition.id                '_diffrn.diffrn_radiation_id'
    _definition.update            2024-11-12
    _description.text
;
    Identifies the characteristics of the radiation source
    for the diffraction data. This is a pointer to
    _diffrn_radiation.id.
;
    _name.category_id             diffrn
    _name.object_id               diffrn_radiation_id
    _name.linked_item_id          '_diffrn_radiation.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
_diffrn.id
CIF 
Unique identifier for a set of particular diffraction conditions.

save_diffrn.id

    _definition.id                '_diffrn.id'
    _definition.update            2022-05-09
    _description.text
;
    Unique identifier for a set of particular diffraction conditions.
;
    _name.category_id             diffrn
    _name.object_id               id
    _type.purpose                 Key
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
DIFFRN_DETECTOR
CIF 
Data items in the DIFFRN_DETECTOR category describe the
detector used to measure the scattered radiation, including
any analyser and post-sample collimation.

save_DIFFRN_DETECTOR

    _definition.id                DIFFRN_DETECTOR
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2025-06-30
    _description.text
;
    Data items in the DIFFRN_DETECTOR category describe the
    detector used to measure the scattered radiation, including
    any analyser and post-sample collimation.
;
    _name.category_id             DIFFRN
    _name.object_id               DIFFRN_DETECTOR

    loop_
      _category_key.name
         '_diffrn_detector.diffrn_id'
         '_diffrn_detector.id'

save_
_diffrn_detector.diffrn_id
CIF 
Code identifying the _diffrn.id to which this detector
relates.

Exists to maintain compatibility with current imgCIF definitions.

save_diffrn_detector.diffrn_id

    _definition.id                '_diffrn_detector.diffrn_id'
    _definition.update            2025-06-30
    _description.text
;
    Code identifying the _diffrn.id to which this detector
    relates.

    Exists to maintain compatibility with current imgCIF definitions.
;
    _name.category_id             diffrn_detector
    _name.object_id               diffrn_id
    _name.linked_item_id          '_diffrn.id'
    _type.purpose                 Link
    _type.source                  Related
    _type.container               Single
    _type.contents                Word

save_
_diffrn_detector.id
CIF 
Unique identifier for a detector description.

save_diffrn_detector.id

    _definition.id                '_diffrn_detector.id'
    _definition.update            2026-05-02
    _description.text
;
    Unique identifier for a detector description.
;
    _name.category_id             diffrn_detector
    _name.object_id               id
    _type.purpose                 Key
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
DIFFRN_MEASUREMENT
CIF 
Data items in the DIFFRN_MEASUREMENT category describe
the sample mounting, positioning and measurement strategy.

save_DIFFRN_MEASUREMENT

    _definition.id                DIFFRN_MEASUREMENT
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2026-04-22
    _description.text
;
    Data items in the DIFFRN_MEASUREMENT category describe
    the sample mounting, positioning and measurement strategy.
;
    _name.category_id             DIFFRACTION
    _name.object_id               DIFFRN_MEASUREMENT
    _category_key.name            '_diffrn_measurement.id'

save_
_diffrn_measurement.diffrn_id
CIF 
A link to a diffraction experiment with which this measurement
strategy is associated. This is provided for backwards compatibility.
Where multiple experiments are associated with a particular strategy,
use _diffrn.diffrn_measurement_id.

save_diffrn_measurement.diffrn_id

    _definition.id                '_diffrn_measurement.diffrn_id'
    _definition.update            2026-04-22
    _description.text
;
    A link to a diffraction experiment with which this measurement
    strategy is associated. This is provided for backwards compatibility.
    Where multiple experiments are associated with a particular strategy,
    use _diffrn.diffrn_measurement_id.
;
    _name.category_id             diffrn_measurement
    _name.object_id               diffrn_id
    _name.linked_item_id          '_diffrn.id'
    _type.purpose                 Link
    _type.source                  Related
    _type.container               Single
    _type.contents                Word

save_
_diffrn_measurement.id
CIF 
Unique identifier for a particular combination of sample mount,
positioner and scan strategy.

save_diffrn_measurement.id

    _definition.id                '_diffrn_measurement.id'
    _definition.update            2026-04-22
    _description.text
;
    Unique identifier for a particular combination of sample mount,
    positioner and scan strategy.
;
    _name.category_id             diffrn_measurement
    _name.object_id               id
    _type.purpose                 Key
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word
    _method.purpose               Definition
    _method.expression
;
    _enumeration.default = _diffrn_measurement.device
;

save_
DIFFRN_RADIATION
CIF 
Data items in the DIFFRN_RADIATION category describe the
radiation used in measuring diffraction intensities. To identify and
assign weights to distinct wavelength components from a polychromatic
beam, see DIFFRN_RADIATION_WAVELENGTH.

save_DIFFRN_RADIATION

    _definition.id                DIFFRN_RADIATION
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2024-11-12
    _description.text
;
    Data items in the DIFFRN_RADIATION category describe the
    radiation used in measuring diffraction intensities. To identify and
    assign weights to distinct wavelength components from a polychromatic
    beam, see DIFFRN_RADIATION_WAVELENGTH.
;
    _name.category_id             DIFFRACTION
    _name.object_id               DIFFRN_RADIATION
    _category_key.name            '_diffrn_radiation.id'

save_
_diffrn_radiation.diffrn_id
CIF 
Code identifying the _diffrn.id to which this radiation description
relates.

Exists to maintain compatibility with current imgCIF definitions.

save_diffrn_radiation.diffrn_id

    _definition.id                '_diffrn_radiation.diffrn_id'
    _definition.update            2025-06-30
    _description.text
;
    Code identifying the _diffrn.id to which this radiation description
    relates.

    Exists to maintain compatibility with current imgCIF definitions.
;
    _name.category_id             diffrn_radiation
    _name.object_id               diffrn_id
    _name.linked_item_id          '_diffrn.id'
    _type.purpose                 Link
    _type.source                  Related
    _type.container               Single
    _type.contents                Word

save_
_diffrn_radiation.id
CIF 
Unique identifier for a radiation source description.

save_diffrn_radiation.id

    _definition.id                '_diffrn_radiation.id'
    _definition.update            2024-11-15
    _description.text
;
    Unique identifier for a radiation source description.
;
    _name.category_id             diffrn_radiation
    _name.object_id               id
    _type.purpose                 Key
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_
DIFFRN_RADIATION_WAVELENGTH
CIF 
Data items in the DIFFRN_RADIATION_WAVELENGTH category describe
the wavelength of the radiation used in measuring the diffraction
intensities. Items may be looped to identify and assign weights to
distinct wavelength components from a polychromatic beam.



save_DIFFRN_RADIATION_WAVELENGTH

    _definition.id                DIFFRN_RADIATION_WAVELENGTH
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2024-11-12
    _description.text
;
    Data items in the DIFFRN_RADIATION_WAVELENGTH category describe
    the wavelength of the radiation used in measuring the diffraction
    intensities. Items may be looped to identify and assign weights to
    distinct wavelength components from a polychromatic beam.

;
    _name.category_id             DIFFRN_RADIATION
    _name.object_id               DIFFRN_RADIATION_WAVELENGTH
    loop_
      _category_key.name
         '_diffrn_radiation_wavelength.id'
         '_diffrn_radiation_wavelength.radiation_id'

save_





_diffrn_radiation_wavelength.radiation_id


CIF 

Code identifying the radiation description to which this wavelength
relates.



save_diffrn_radiation_wavelength.radiation_id

    _definition.id                '_diffrn_radiation_wavelength.radiation_id'
    _definition.update            2024-11-12
    _description.text
;
    Code identifying the radiation description to which this wavelength
    relates.
;
    _name.category_id             diffrn_radiation_wavelength
    _name.object_id               radiation_id
    _name.linked_item_id          '_diffrn_radiation.id'
    _type.purpose                 Link
    _type.source                  Related
    _type.container               Single
    _type.contents                Word

save_









DIFFRN_REFLN
CIF 

Data items in the DIFFRN_REFLN category record details about
the intensities measured in the diffraction experiment,
prior to data reduction and merging.



save_DIFFRN_REFLN

    _definition.id                DIFFRN_REFLN
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2026-06-11
    _description.text
;
    Data items in the DIFFRN_REFLN category record details about
    the intensities measured in the diffraction experiment,
    prior to data reduction and merging.
;
    _name.category_id             DIFFRN
    _name.object_id               DIFFRN_REFLN

    loop_
      _category_key.name
         '_diffrn_refln.diffrn_id'
         '_diffrn_refln.id'

save_





_diffrn_refln.diffrn_id


CIF 

A code which identifies the diffraction conditions under which the data for
reflection measurements were collected.



save_diffrn_refln.diffrn_id

    _definition.id                '_diffrn_refln.diffrn_id'
    _definition.update            2026-06-11
    _description.text
;
    A code which identifies the diffraction conditions under which the data for
    reflection measurements were collected.
;
    _name.category_id             diffrn_refln
    _name.object_id               diffrn_id
    _name.linked_item_id          '_diffrn.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_









DIFFRN_SOURCE
CIF 

Data items in the DIFFRN_SOURCE category record details of
the source of radiation used in the diffraction experiment.



save_DIFFRN_SOURCE

    _definition.id                DIFFRN_SOURCE
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2025-06-18
    _description.text
;
    Data items in the DIFFRN_SOURCE category record details of
    the source of radiation used in the diffraction experiment.
;
    _name.category_id             DIFFRN
    _name.object_id               DIFFRN_SOURCE
    _category_key.name            '_diffrn_source.radiation_id'

save_





_diffrn_source.radiation_id


CIF 

Identifies the characteristics of the radiation source.
This is a pointer to _diffrn_radiation.id.



save_diffrn_source.radiation_id

    _definition.id                '_diffrn_source.radiation_id'
    _definition.update            2025-06-18
    _description.text
;
    Identifies the characteristics of the radiation source.
    This is a pointer to _diffrn_radiation.id.
;
    _name.category_id             diffrn_source
    _name.object_id               radiation_id
    _name.linked_item_id          '_diffrn_radiation.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_









EXPTL_CRYSTAL
CIF 

Data items in the EXPTL_CRYSTAL category record details about
experimental measurements on the crystal or crystals used,
such as shape, size or density.



save_EXPTL_CRYSTAL

    _definition.id                EXPTL_CRYSTAL
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2022-05-09
    _description.text
;
    Data items in the EXPTL_CRYSTAL category record details about
    experimental measurements on the crystal or crystals used,
    such as shape, size or density.
;
    _name.category_id             EXPTL
    _name.object_id               EXPTL_CRYSTAL
    _category_key.name            '_exptl_crystal.id'

save_





_exptl_crystal.id


CIF 

Code identifying a crystal.

Also known as: _exptl_crystal_id



save_exptl_crystal.id

    _definition.id                '_exptl_crystal.id'
    _alias.definition_id          '_exptl_crystal_id'
    _definition.update            2022-05-09
    _description.text
;
    Code identifying a crystal.
;
    _name.category_id             exptl_crystal
    _name.object_id               id
    _type.purpose                 Key
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_









REFLN
CIF 

Data items in the REFLN category record details about the
reflections used to determine the ATOM_SITE data items.



save_REFLN

    _definition.id                REFLN
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2026-05-19
    _description.text
;
    Data items in the REFLN category record details about the
    reflections used to determine the ATOM_SITE data items.
;
    _name.category_id             DIFFRACTION
    _name.object_id               REFLN

    loop_
      _category_key.name
         '_refln.id'
         '_refln.structure_id'

save_





_refln.structure_id


CIF 

A code identifying the crystallographic structure associated with this
reflection.



save_refln.structure_id

    _definition.id                '_refln.structure_id'
    _definition.update            2026-05-19
    _description.text
;
    A code identifying the crystallographic structure associated with this
    reflection.
;
    _name.category_id             refln
    _name.object_id               structure_id
    _name.linked_item_id          '_structure.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_









SPACE_GROUP
CIF 

Data items in the SPACE_GROUP category are used to specify space-group
information about the crystal used in the diffraction measurements.

Space-group types are identified by their number as listed in
International Tables for Crystallography Volume A, or by their
Schoenflies symbol. Specific settings of the space groups can
be identified by their Hall symbol, by specifying their
symmetry operations or generators, or by giving the
transformation that relates the specific setting to the
reference setting based on International Tables Volume A and
stored in the core CIF dictionary.

The commonly used Hermann-Mauguin symbol determines the
space-group type uniquely, but several different Hermann-Mauguin
symbols may refer to the same space-group type. A
Hermann-Mauguin symbol contains information on the choice of
the basis, but not on the choice of origin.

Ref: International Tables for Crystallography (2016). Volume A,

Space-group symmetry, edited by M. I. Aroyo, 6th ed.
Chichester: John Wiley & Sons.



save_SPACE_GROUP

    _definition.id                SPACE_GROUP
    _definition.scope             Category
    _definition.class             Set
    _definition.update            2023-10-16
    _description.text
;
    Data items in the SPACE_GROUP category are used to specify space-group
    information about the crystal used in the diffraction measurements.

    Space-group types are identified by their number as listed in
    International Tables for Crystallography Volume A, or by their
    Schoenflies symbol. Specific settings of the space groups can
    be identified by their Hall symbol, by specifying their
    symmetry operations or generators, or by giving the
    transformation that relates the specific setting to the
    reference setting based on International Tables Volume A and
    stored in the core CIF dictionary.

    The commonly used Hermann-Mauguin symbol determines the
    space-group type uniquely, but several different Hermann-Mauguin
    symbols may refer to the same space-group type. A
    Hermann-Mauguin symbol contains information on the choice of
    the basis, but not on the choice of origin.

    Ref: International Tables for Crystallography (2016). Volume A,
         Space-group symmetry, edited by M. I. Aroyo, 6th ed.
         Chichester: John Wiley & Sons.
;
    _name.category_id             EXPTL
    _name.object_id               SPACE_GROUP
    _category_key.name            '_space_group.id'

save_





_space_group.id


CIF 

Unique identifier for a space group.

Two space groups can share the same identifier if and only if they have
the same space group name, number and setting, and have their symmetry
operations listed with the same symop ids (see SPACE_GROUP_SYMOP).



save_space_group.id

    _definition.id                '_space_group.id'
    _definition.update            2023-10-25
    _description.text
;
    Unique identifier for a space group.

    Two space groups can share the same identifier if and only if they have
    the same space group name, number and setting, and have their symmetry
    operations listed with the same symop ids (see SPACE_GROUP_SYMOP).
;
    _name.category_id             space_group
    _name.object_id               id
    _type.purpose                 Key
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_









SPACE_GROUP_GENERATOR
CIF 

Data items in the SPACE_GROUP_GENERATOR category list
generators for a space group.



save_SPACE_GROUP_GENERATOR

    _definition.id                SPACE_GROUP_GENERATOR
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2025-04-29
    _description.text
;
    Data items in the SPACE_GROUP_GENERATOR category list
    generators for a space group.
;
    _name.category_id             SPACE_GROUP
    _name.object_id               SPACE_GROUP_GENERATOR

    loop_
      _category_key.name
         '_space_group_generator.id'
         '_space_group_generator.space_group_id'

save_





_space_group_generator.space_group_id


CIF 

A code which identifies the space group to which the generator belongs.



save_space_group_generator.space_group_id

    _definition.id                '_space_group_generator.space_group_id'
    _definition.update            2023-01-17
    _description.text
;
    A code which identifies the space group to which the generator belongs.
;
    _name.category_id             space_group_generator
    _name.object_id               space_group_id
    _name.linked_item_id          '_space_group.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_









SPACE_GROUP_SYMOP
CIF 

Data items in the SPACE_GROUP_SYMOP category are used to
describe symmetry-equivalent sites in the crystal unit cell.



save_SPACE_GROUP_SYMOP

    _definition.id                SPACE_GROUP_SYMOP
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2023-10-16
    _description.text
;
    Data items in the SPACE_GROUP_SYMOP category are used to
    describe symmetry-equivalent sites in the crystal unit cell.
;
    _name.category_id             SPACE_GROUP
    _name.object_id               SPACE_GROUP_SYMOP

    loop_
      _category_key.name
         '_space_group_symop.id'
         '_space_group_symop.space_group_id'

save_





_space_group_symop.space_group_id


CIF 

A code which identifies the space group to which the symop belongs.



save_space_group_symop.space_group_id

    _definition.id                '_space_group_symop.space_group_id'
    _definition.update            2023-01-17
    _description.text
;
    A code which identifies the space group to which the symop belongs.
;
    _name.category_id             space_group_symop
    _name.object_id               space_group_id
    _name.linked_item_id          '_space_group.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_









SPACE_GROUP_WYCKOFF
CIF 

Data items in the SPACE_GROUP_WYCKOFF category
contain information about Wyckoff positions of a space group.
Only one site can be given for each special position, but the
remainder can be generated by applying the symmetry operations
stored in _space_group_symop.operation_xyz.



save_SPACE_GROUP_WYCKOFF

    _definition.id                SPACE_GROUP_WYCKOFF
    _definition.scope             Category
    _definition.class             Loop
    _definition.update            2023-10-16
    _description.text
;
    Data items in the SPACE_GROUP_WYCKOFF category
    contain information about Wyckoff positions of a space group.
    Only one site can be given for each special position, but the
    remainder can be generated by applying the symmetry operations
    stored in _space_group_symop.operation_xyz.
;
    _name.category_id             SPACE_GROUP
    _name.object_id               SPACE_GROUP_WYCKOFF

    loop_
      _category_key.name
         '_space_group_Wyckoff.id'
         '_space_group_Wyckoff.space_group_id'

save_





_space_group_Wyckoff.space_group_id


CIF 

A code which identifies the space group to which the Wyckoff position
belongs.



save_space_group_wyckoff.space_group_id

    _definition.id                '_space_group_Wyckoff.space_group_id'
    _definition.update            2023-01-17
    _description.text
;
    A code which identifies the space group to which the Wyckoff position
    belongs.
;
    _name.category_id             space_group_Wyckoff
    _name.object_id               space_group_id
    _name.linked_item_id          '_space_group.id'
    _type.purpose                 Link
    _type.source                  Assigned
    _type.container               Single
    _type.contents                Word

save_









Revision history




Version 1.0.0 (2023-09-15) All multi-block items from core 3.2.0 added.


Version 1.1.0 (2026-11-03) Add STRUCTURE and related data names and links, including
       REFLN, CELL, ATOM_SITE, and ATOM_SITES_* categories.

       Added _model.id as key to MODEL and added child key data names
       to GEOM_* and MODEL_SITE categories.

       Add DIFFRN_SOURCE category with _diffrn_source.radiation_id key data
       name.

       Add DIFFRN_DETECTOR category with _diffrn_detector.id and
        _diffrn_detector.diffrn_id key data names. Included
        _diffrn_detector.diffrn_id to maintain compatibility with imgCIF.

       Add DIFFRN_RADIATION category with _diffrn_radiation.id as key. Included
        _diffrn_radiation.diffrn_id to maintain compatibility with imgCIF.

       Add DIFFRN_MEASUREMENT category with _diffrn_measurement.id as key.
       Included _diffrn_measurement.diffrn_id to maintain compatibility with
       imgCIF.

       Added _diffrn_refln.diffrn_id is linked key to DIFFRN_REFLN.

       Renamed dictionary to CIF_CORE_MULTIBLOCK and adjusted the head
       category name accordingly.









 





        
        
        

          

          

          

          

          

          

          

          

          

          

          

          

          

          

          

          

          

          

          

          

          

        

      

    
   

      
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