CIF_COD

Version: 0.050 (2020-07-15)

  1. COD_DATA_SOURCE
    1. _cod_data_source_file
    2. _cod_data_source_block
    3. _cod_data_source_URI
    4. _cod_data_source_URL
    5. _cod_data_source_URN
    6. _cod_data_source_MD5_sum
    7. _cod_data_source_SHA1_sum
    8. _cod_data_source_SHA256_sum
  2. COD_DATABASE_CODE
    1. _cod_database_code_structure
    2. _cod_database_code
    3. _cod_database_code_diffrn_file
  3. COD_RELATED_DIFFRN_FILE
    1. _cod_related_diffrn_file_code
    2. _cod_database_fobs_code
  4. COD_RELATED_STRUCTURE_ENTRY
    1. _cod_related_structure_entry_code
    2. _cod_database_coordinates_code
  5. COD_RELATED_DUPLICATE_ENTRY
    1. _cod_related_duplicate_entry_code
    2. _cod_duplicate_entry
  6. COD_RELATED_OPTIMAL_ENTRY
    1. _cod_related_optimal_entry_code
    2. _cod_related_optimal_struct
  7. COD_RELATED_SUBOPTIMAL_ENTRY
    1. _cod_related_suboptimal_entry_code
    2. _cod_related_suboptimal_struct
  8. COD_RELATED_ENANTIOMER_ENTRY
    1. _cod_related_enantiomer_entry_code
    2. _cod_enantiomer_of
  9. COD_RELATED_SAME_STRUCTURE_ENTRY
    1. _cod_related_same_structure_entry_code
    2. _cod_same_crystal_as
  10. COD_RELATED_ENTRY
    1. _cod_related_entry_id
    2. _cod_related_entry
    3. _cod_related_entry_code
    4. _cod_related_entry_database
    5. _cod_related_entry_description
    6. _cod_related_entry_uri
  11. COD_ORIGINAL
    1. _cod_original_cell_volume
    2. _cod_original_formula_weight
    3. _cod_original_formula_units_Z
    4. _cod_original_formula_structural
    5. _cod_original_formula_sum
    6. _cod_original_formula_moiety
    7. _cod_original_formula_iupac
    8. _cod_original_sg_symbol_H-M
    9. _cod_original_sg_symbol_Hall
    10. _cod_original_sg_number
    11. _cod_chemical_formula_sum_orig
    12. _cod_chemical_formula_moiety_orig
    13. _cod_cif_authors_sg_H-M
    14. _cod_cif_authors_sg_Hall
    15. _cod_cif_authors_sg_number
  12. COD_STRUCTURE
    1. _cod_structure_determination_method
    2. _cod_struct_determination_method
  13. COD_CHANGELOG_ENTRY
    1. _cod_changelog_entry_id
    2. _cod_changelog_entry_author
    3. _cod_changelog_entry_date
    4. _cod_changelog_entry_text
  14. COD_DEPOSITOR
    1. _cod_depositor_requested_release_date
    2. _cod_hold_until_date
    3. _cod_depositor_comments
  15. COD_ENTRY_ISSUE
    1. _cod_entry_issue_id
    2. _cod_entry_issue_origin
    3. _cod_entry_issue_severity
    4. _cod_entry_issue_description
    5. _cod_entry_issue_author
    6. _cod_entry_issue_date

COD_DATA_SOURCE

Data items from this category are used to record and trace sources of information deposited into the COD.

Examples:

ValueDescription

_cod_data_source_file    bq2131.cif
_cod_data_source_block   I
Example based on COD entry 2221282, revision 176789. svn://www.crystallography.net/cod/cif/2/22/12/2221282.cif [http://www.crystallography.net/cod/2221282.cif@176789](http://www.crystallography.net/cod/2221282.cif@176789)

_cod_data_source_file

Specifies the name of the file that served as the source of the data for the given COD entry. The file name should be recorded without the path or other URL components since these components usually have no sense on the recipient's system. In Unix parlance, the recorded value should consists of the basename of the original file. If case the full persistent URI is known, the _cod_data_source_URI, _cod_data_source_URN or _cod_data_source_URL data items should be used to record it instead.

For many data sources, however, the basename contains enough information to locate the original source of information. For example, CIFs published in IUCr journals have a Coeditor Code as a CIF file name that can be used to identify the original paper where the structure is discussed.

_cod_data_source_block

Specifies the name of the data block within the file that served as a source of data for the given COD entry (see _cod_data_source_file). Only the data block code following the 'data_' header keyword should be recorded. For example, if the data block starts with the 'data_I' header, only the 'I' should be recorder as the data value.

_cod_data_source_URI

Specifies the uniform resource identifier (URI) of the file that served as a source of data for the given COD entry (see _cod_data_source_file).

_cod_data_source_URL

Specifies the uniform resource locator (URL) of the file that served as a source of data for the given COD entry (see _cod_data_source_file).

_cod_data_source_URN

Specifies the uniform resource name (URN) of the file that served as a source of data for the given COD entry (see _cod_data_source_file).

_cod_data_source_MD5_sum

Specifies the MD5 cryptographic checksum of the file that served as a source of data for the given COD entry. The checksum should be computed from the same file that is referenced using the _cod_data_source_file data item.

_cod_data_source_SHA1_sum

Specifies the SHA1 cryptographic checksum of the file that served as a source of data for the given COD entry. The checksum should be computed from the same file that is referenced using the _cod_data_source_file data item.

_cod_data_source_SHA256_sum

Specifies the SHA256 cryptographic checksum of the file that served as a source of data for the given COD entry. The checksum should be computed from the same file that is referenced using the _cod_data_source_file data item.

COD_DATABASE_CODE

Data items in the COD_DATABASE_CODE category record various persistent unique identifiers used in the COD.

Examples:

ValueDescription

data_2011000
_cod_database_code 2011000
Example based on COD entry 2011000, revision 176760. svn://www.crystallography.net/cod/cif/2/01/10/2011000.cif@176760 [http://www.crystallography.net/cod/2011000.cif@176760](http://www.crystallography.net/cod/2011000.cif@176760)

_cod_database_code_structure

A persistent unique identifier assigned to each crystal structure upon successful deposition to the COD. The identifier is guaranteed not to change and is the preferred way of referencing individual COD entries.

The identifier is sometimes also referred to as "COD number", however, the term "COD ID" is favoured in formal documentation.

This data item is intended to be placed exclusively in crystal structure data files curated by the COD.

Examples:

ValueDescription
2015004 COD ID that uniquely identifies COD entry 2015004. Example based on COD entry 2015004, revision 201957. svn://www.crystallography.net/cod/cif/2/01/50/2015004.cif@201957 [http://www.crystallography.net/cod/2015004.cif@201957](http://www.crystallography.net/cod/2015004.cif@201957)

_cod_database_code

A persistent unique identifier assigned to each crystal structure upon successful deposition to the COD. The identifier is guaranteed not to change and is the preferred way of referencing individual COD entries.

The identifier is sometimes also referred to as "COD number", however, the term "COD ID" is favoured in formal documentation.

This data item is intended to be placed exclusively in crystal structure data files curated by the COD.

Examples:

ValueDescription
2015004 COD ID that uniquely identifies COD entry 2015004. Example based on COD entry 2015004, revision 201957. svn://www.crystallography.net/cod/cif/2/01/50/2015004.cif@201957 [http://www.crystallography.net/cod/2015004.cif@201957](http://www.crystallography.net/cod/2015004.cif@201957)

_cod_database_code_diffrn_file

A persistent unique identifier assigned to each diffraction data file upon successful deposition to the COD. The term "COD DIFFRN ID" is used in formal documentation to refer to this identifier.

Normally, the COD DIFFRN ID assigned to the structure factor (a.k.a. Fobs) file matches the one assigned to the corresponding crystal structure entry (see _cod_database_code_structure).

Data of powder diffraction experiments are handled slightly differently since a single set of diffractograms can be used in the refinement of multiple phases. In such cases, diffractograms from the same set are recorded in separate data blocks of a single file and all assigned the same COD DIFFRN ID. The COD DIFFRN ID can then be referenced by each refined phase (see _cod_related_diffrn_file_code). The phases themselves, however, are each assigned a unique COD ID. It is recommended, although not required, that the COD DIFFRN ID of the diffractogram set matches the COD ID assigned to the first phase of the experiment.

This data item is intended to be placed exclusively in diffraction data files curated by the COD.

COD_RELATED_DIFFRN_FILE

Data items in the COD_RELATED_DIFFRN_FILE category record references to diffraction datasets that were used to solve the given crystal structure. The category is intended to be used with diffraction datasets that have been deposited to the COD and assigned persistent unique identifiers.

_cod_related_diffrn_file_code

Records the COD DIFFRN ID of a COD diffraction file that was used to solve the given crystal structure entry, i.e. the entry containing this data item.

This data item is intended to be placed exclusively in crystal structure data files curated by the COD.

_cod_database_fobs_code

Records the COD DIFFRN ID of a COD diffraction file that was used to solve the given crystal structure entry, i.e. the entry containing this data item.

This data item is intended to be placed exclusively in crystal structure data files curated by the COD.

COD_RELATED_STRUCTURE_ENTRY

Data items in the COD_RELATED_STRUCTURE_ENTRY category record references to crystal structures that were solved using the given diffraction dataset. The category is intended to be used with crystal structures that have been deposited to the COD and assigned persistent unique identifiers.

_cod_related_structure_entry_code

Records the COD IDs of a crystal structure entries that were solved using the given diffraction file, i.e. the file containing this data item.

In case a diffraction data file contains more than one data block, each data block should have its own instance of this data item. A typical example of such situation would be a powder diffraction file with several diffractograms each stored in a separate data block (see _cod_database_code_diffrn_file).

This data item is intended to be placed exclusively in diffraction data files curated by the COD.

_cod_database_coordinates_code

Records the COD IDs of a crystal structure entry that was solved using the given diffraction file, i.e. the file containing this data item.

In case a diffraction data file contains more than one data block, each data block should have its own instance of this data item. A typical example of such situation would be a powder diffraction file with several diffractograms each stored in a separate data block (see _cod_database_code_diffrn_file).

This data item is intended to be placed exclusively in diffraction data files curated by the COD.

COD_RELATED_DUPLICATE_ENTRY

Data items in the COD_RELATED_DUPLICATE_ENTRY category record references to duplicate COD entries.

Entries are considered duplicates of each other if they originate from the same publication and carry exactly the same information. The COD actively safeguards against the inclusion of such entries, however, historically some duplicates have been assigned distinct COD IDs. Since COD ID assignment is permanent these entries cannot simply be removed from the database and are instead marked using appropriate data items when noticed.

The duplicate relationship is modelled as unidirectional and intransitive. As a result, the referenced entry itself must not contain any references of this kind. For example, if three entries are all duplicates of each other, one of them should be selected as the main one and the remaining two entries should both reference it. The selected main entry must contain the most complete and comprehensive structure description of all of the duplicates.

Care should be taken to exclude these duplicate entries from computations and statistics.

Examples:

ValueDescription

data_1000000
_cod_database_code                1000000
_cod_related_duplicate_entry_code 2011331
COD entries 1000000 and 2100858 are marked as duplicates of each other. The provided example only showcases a reference from entry 1000000 to entry 2100858. Due to the unidirectional and intransitive nature of the relationship entry 2100858 is considered the main one and should not contain references of this kind. Entry 2100858 was chosen as the main one due to it being more complete than entry 1000000. Example based on COD entry 1000000, revision 212039. svn://www.crystallography.net/cod/cif/1/00/00/1000000.cif@212039 [http://www.crystallography.net/cod/1000000.cif@212039](http://www.crystallography.net/cod/1000000.cif@212039)

_cod_related_duplicate_entry_code

Records the COD ID of an entry that is considered to be a duplicate of the given COD entry, i.e. the entry containing this data item.

The duplicate relationship is modelled as unidirectional and intransitive. As a result, the referenced entry itself must not contain any references of this kind. For example, if three entries are all duplicates of each other, one of them should be selected as the main one and the remaining two entries should both reference it. The selected main entry must contain the most complete and comprehensive structure description of all of the duplicates.

Care should be taken to exclude these duplicate entries from computations and statistics.

_cod_duplicate_entry

Records the COD ID of an entry that is considered to be a duplicate of the given COD entry, i.e. the entry containing this data item.

The duplicate relationship is modelled as unidirectional and intransitive. As a result, the referenced entry itself must not contain any references of this kind. For example, if three entries are all duplicates of each other, one of them should be selected as the main one and the remaining two entries should both reference it. The selected main entry must contain the most complete and comprehensive structure description of all of the duplicates.

Care should be taken to exclude these duplicate entries from computations and statistics.

COD_RELATED_OPTIMAL_ENTRY

Data items in the COD_RELATED_OPTIMAL_ENTRY category record references to COD entries that describe structures solved in an optimal manner.

Data items in this category must only be used to record relationships between entries originating from the same publication, for instance, to relate the optimal interpretation to the suboptimal ones that were only included for comparison purposes.

Only the optimal structures should be used for computations and statistics except when purposely comparing the optimal structure with the related suboptimal ones (see COD_RELATED_SUBOPTIMAL_ENTRY).

Examples:

ValueDescription

data_2100860
_cod_database_code               2100860
_cod_related_optimal_entry_code  2100858
COD entry 2100860 refers to COD entry 2100858 as being the optimal one. This implies that the COD entry 2100860 itself describes the suboptimally solved structure. Example based on COD entry 2100860, revision 212039. svn://www.crystallography.net/cod/cif/2/10/08/2100860.cif@212039 [http://www.crystallography.net/cod/2100860.cif@212039](http://www.crystallography.net/cod/2100860.cif@212039)

_cod_related_optimal_entry_code

Records the COD ID of an entry that describes the optimally solved structure as compared to the given suboptimal COD entry, i.e. the entry containing this data item.

Entries marked as optimal must originate from the same publication as the suboptimal ones. For example, the suboptimal structures might be provided by the authors to demonstrate that an alternative space group choice or a structure solution method are indeed inferior.

It is recommended that the suboptimal entries be reciprocally referenced by the optimal entry (see COD_RELATED_SUBOPTIMAL_ENTRY).

_cod_related_optimal_struct

Records the COD ID of an entry that describes the optimally solved structure as compared to the given suboptimal COD entry, i.e. the entry containing this data item.

Entries marked as optimal must originate from the same publication as the suboptimal ones. For example, the suboptimal structures might be provided by the authors to demonstrate that an alternative space group choice or a structure solution method are indeed inferior.

It is recommended that the suboptimal entries be reciprocally referenced by the optimal entry (see COD_RELATED_SUBOPTIMAL_ENTRY).

COD_RELATED_SUBOPTIMAL_ENTRY

Data items in the COD_RELATED_SUBOPTIMAL_ENTRY category record references to COD entries that describe structures solved in a suboptimal manner.

Data items in this category must only be used to record relationships between entries originating from the same publication, for instance, to refer to interpretations of the structural data that were deliberately processed in a suboptimal way and are only provided for comparison purposes.

Care should be taken to exclude such suboptimal structures from computations and statistics except when purposely comparing them with the related optimal structure (see COD_RELATED_OPTIMAL_ENTRY).

Examples:

ValueDescription

data_2100858
_cod_database_code               2100858
loop_
_cod_related_suboptimal_entry_code
2100860
2100862
COD entry 2100858 refers to COD entries 2100860 and 2100862 as being the suboptimal ones. This implies that the COD entry 2100858 itself describes the optimally solved structure. Example based on COD entry 2100858, revision 212039. svn://www.crystallography.net/cod/cif/2/10/08/2100858.cif@212039 [http://www.crystallography.net/cod/2100858.cif@212039](http://www.crystallography.net/cod/2100858.cif@212039)

_cod_related_suboptimal_entry_code

Records COD IDs of entries that describe suboptimally solved structures as compared to the given optimal COD entry, i.e. the entry containing this data item.

Entries marked as suboptimal must originate from the same publication as the optimal one. For example, the suboptimal structures might be provided by the authors to complement the structure solution strategy discussion.

It is recommended that the optimal entry be reciprocally referenced by the suboptimal entries (see COD_RELATED_OPTIMAL_ENTRY).

_cod_related_suboptimal_struct

Records COD IDs of entries that describe suboptimally solved structures as compared to the given optimal COD entry, i.e. the entry containing this data item.

Entries marked as suboptimal must originate from the same publication as the optimal one. For example, the suboptimal structures might be provided by the authors to complement the structure solution strategy discussion.

It is recommended that the optimal entry be reciprocally referenced by the suboptimal entries (see COD_RELATED_OPTIMAL_ENTRY).

COD_RELATED_ENANTIOMER_ENTRY

Data items in the COD_RELATED_ENANTIOMER_ENTRY category record enantiomeric relationships between COD entries.

Data items in this category must only be used to record relationships between entries originating from the same publication.

Examples:

ValueDescription

data_4105625
_cod_database_code               4105625
loop_
_cod_related_enantiomer_entry_code
4105851
COD entries 4105625 and 4105851 are marked as describing structures that are enantiomers of each other. The provided example only showcases a reference from entry 4105625 to entry 4105851, however, it is reasonable to expect that a reciprocal reference from entry 4105851 to entry 4105625 is also defined. Example based on COD entry 4105625, revision 212039. svn://www.crystallography.net/cod/cif/4/10/56/4105625.cif@212039 [http://www.crystallography.net/cod/4105625.cif@212039](http://www.crystallography.net/cod/4105625.cif@212039)

data_0555010
_cod_database_code               0555010
loop_
_cod_related_enantiomer_entry_code
0555013
0555014
0555015
COD entry 0555010 is marked as containing an enantiomer structure as compared to entries 0555013, 0555014, 0555015. Entries 0555013, 0555014, 0555015 all contain structures of the same enantiomer. Example describes a hypothetical situation and is not based on real COD structures.

_cod_related_enantiomer_entry_code

Records COD IDs of entries that describe structures of enantiomers as compared to the given COD entry, i.e. the entry containing this data item.

Entries marked as having the enantiomeric relationship must all originate from the same publication.

Normally, an enantiomeric relationship is a pairwise one, however, it is possible for a single publication to yield several structures of the same enantiomer. In cases like these all of the corresponding enantiomer entries should be referenced.

Due to the symmetrical nature of the enantiomeric relationship it is recommended that the referenced entries also contain reciprocal references.

_cod_enantiomer_of

Records COD IDs of entries that describe structures of enantiomers as compared to the given COD entry, i.e. the entry containing this data item.

Entries marked as having the enantiomeric relationship must all originate from the same publication.

Normally, an enantiomeric relationship is a pairwise one, however, it is possible for a single publication to yield several structures of the same enantiomer. In cases like these all of the corresponding enantiomer entries should be referenced.

Due to the symmetrical nature of the enantiomeric relationship it is recommended that the referenced entries also contain reciprocal references.

COD_RELATED_SAME_STRUCTURE_ENTRY

Data items in the COD_RELATED_SAME_STRUCTURE_ENTRY category record relationships between COD entries that describe nearly identical structures solved using the measurements of the same crystal.

It is assumed that entries related in this way contain almost exactly the same information and mainly only differ by originating from different publications. For example, it is not uncommon for authors to include previously published structures as a supplementary material of their own work to showcase a trend or for comparison purposes. Since each COD entry records the fact that a structure has been published in a peer-reviewed source such structures are intentionally included into the COD and should not be considered duplicate entries (see COD_RELATED_DUPLICATE_ENTRY).

The same structure relationship is modelled as unidirectional and intransitive. As a result, the referenced entry itself must not contain any references of this kind. For example, if three entries all describe the same structure, one of them should be selected as the main one and the remaining two entries should both reference it. The selected main entry must be published prior to all of the other related entries.

Entries related in this way all share almost exactly the same information therefore care should be taken to only include the main structure in computations and statistics.

Examples:

ValueDescription

data_4060527
_cod_database_code                      4060527
_cod_related_same_structure_entry_code  4062828
COD entries 4060527 and 4062828 are marked as describing nearly identical structures derived from the measurements of the the same crystal. The provided example only showcases a reference from entry 4060527 to entry 4062828. Due to the unidirectional and intransitive nature of the relationship entry 4062828 is considered the main one and should not contain references of this kind. Entry 4062828 was chosen as the main one due to it originating from a source published a year earlier than the one entry 4060527 originates from. Example based on COD entry 4060527, revision 212377. svn://www.crystallography.net/cod/cif/4/10/56/4105625.cif@212377 [http://www.crystallography.net/cod/4105625.cif@212377](http://www.crystallography.net/cod/4105625.cif@212377)

_cod_related_same_structure_entry_code

Records the COD ID of an entry that describes a nearly identical structure solved using the measurements of the same crystal as the given COD entry, i.e. the entry containing this data item.

The same structure relationship is modelled as unidirectional and intransitive. As a result, the referenced entry itself must not contain any references of this kind. For example, if three entries all describe the same crystal structure, one of them should be selected as the main one and the remaining two entries should both reference it. The selected main entry must be published prior to all of the other related entries.

Entries related in this way all share almost exactly the same information therefore care should be taken to only include the main structure in computations and statistics.

_cod_same_crystal_as

Records the COD ID of an entry that describes a nearly identical structure solved using the measurements of the same crystal as the given COD entry, i.e. the entry containing this data item.

The same structure relationship is modelled as unidirectional and intransitive. As a result, the referenced entry itself must not contain any references of this kind. For example, if three entries all describe the same crystal structure, one of them should be selected as the main one and the remaining two entries should both reference it. The selected main entry must be published prior to all of the other related entries.

Entries related in this way all share almost exactly the same information therefore care should be taken to only include the main structure in computations and statistics.

COD_RELATED_ENTRY

The CATEGORY of data items used to describe the relationship between a COD entry and related entries in the COD or other databases.

_cod_related_entry_id

Value is a unique key to a set of COD_RELATED_ENTRY items in a looped list.

_cod_related_entry

The unique identifier of the related entry assigned by the related database (see _cod_related_entry_database).

_cod_related_entry_code

The unique identifier of the related entry assigned by the related database (see _cod_related_entry_database).

Examples:

ValueDescription
1KNV A unique identifier of a crystal structure in the PDB.
Q42 A unique identifier of a Wikidata entry.
5429 A unique compound identifier (CID) assigned by PubChem.

_cod_related_entry_database

The name of the database that stores the related entry.

Examples:

ValueDescription
COD Crystallography Open Database.
PDB Protein Data Bank
AMCSD American Mineralogist Crystal Structure Database
PubChem PubChem
ChemSpider ChemSpider

_cod_related_entry_description

A short description detailing the nature of the relationship between the entry in the COD and the one in the related database.

_cod_related_entry_uri

The uniform resource identifier (URI) of the related entry (see _cod_related_entry_code).

COD_ORIGINAL

Data items in the COD_ORIGINAL category record the original values of certain data items that were changed during the COD data curation process.

Examples:

ValueDescription

_cell_angle_alpha                90.
_cell_angle_beta                 90.
_cell_angle_gamma                90.
_cell_formula_units_Z            2
_cell_length_a                   3.884
_cell_length_b                   3.884
_cell_length_c                   12.6
_cell_volume                     190.077

_chemical_formula_sum            'O4 Sr2 Ti'

_cod_original_cell_volume        190.08
_cod_original_formula_sum        'O4 Sr2 Ti1'
This example includes extracts from other categories as supplied by the author/depositor. Note that the COD_ORIGINAL category contains data items analogous to those in several different core categories and should be regarded as a bookkeeping category. Example based on COD entry 1517788, revision 177091. svn://www.crystallography.net/cod/cif/1/51/77/1517788.cif@177091 [http://www.crystallography.net/cod/1517788.cif@177091](http://www.crystallography.net/cod/1517788.cif@177091)

_cod_original_cell_volume

Original crystal unit cell volume provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _cell_volume data item).

_cod_original_formula_weight

Original chemical formula mass in daltons provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _chemical_formula_weight data item).

_cod_original_formula_units_Z

Original number of the formula units in the unit cell provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _cell_formula_units_Z data item).

_cod_original_formula_structural

Original value of the _chemical_formula_structural data item as reported by the CIF authors. Should be recorded if the _chemical_formula_structural data item value was changed during the COD data curation process.

_cod_original_formula_sum

Original chemical formula in which all discrete bonded residues and ions are summed over the constituent elements following the Hill system ordering provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _chemical_formula_sum data item).

_cod_original_formula_moiety

Original chemical formula with each discrete bonded residue or ion shown as a separate moiety provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _chemical_formula_moiety data item).

_cod_original_formula_iupac

Original chemical formula expressed in conformance with IUPAC rules for inorganic and metal-organic compounds where these conflict with the rules for any other data items from the CHEMICAL_FORMULA category provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _chemical_formula_iupac data item).

_cod_original_sg_symbol_H-M

Original Hermann-Mauguin space group symbol provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _space_group_name_H-M_alt data item).

_cod_original_sg_symbol_Hall

Original space group symbol as described by Hall provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _space_group_name_Hall data item).

_cod_original_sg_number

Original space group number from International Tables for Crystallography Vol. A (2002) provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _space_group_IT_number data item).

_cod_chemical_formula_sum_orig

Original chemical formula in which all discrete bonded residues and ions are summed over the constituent elements following the Hill system ordering provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _chemical_formula_sum data item).

_cod_chemical_formula_moiety_orig

Original chemical formula with each discrete bonded residue or ion shown as a separate moiety provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _chemical_formula_moiety data item).

_cod_cif_authors_sg_H-M

Original Hermann-Mauguin space group symbol provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _space_group_name_H-M_alt data item).

_cod_cif_authors_sg_Hall

Original space group symbol as described by Hall provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _space_group_name_Hall data item).

_cod_cif_authors_sg_number

Original space group number from International Tables for Crystallography Vol. A (2002) provided by the CIF authors. Should be provided if it is different from the value computed by the COD scripts (stored using the regular _space_group_IT_number data item).

COD_STRUCTURE

Data items in the COD_STRUCTURE category record details about the crystal structure.

Examples:

ValueDescription

data_1546034
_cod_database_code                    1546034
_cod_structure_determination_method   'powder diffraction'
COD entry 1546034 is marked as being determined in a powder diffraction experiment. Example based on COD entry 1546034, revision 212039. svn://www.crystallography.net/cod/cif/1/54/60/1546034.cif@212039 [http://www.crystallography.net/cod/1546034.cif@212039](http://www.crystallography.net/cod/1546034.cif@212039)

_cod_structure_determination_method

Specifies the method that was used to determine the crystal structure.

Values:

ValueDescription
single crystalCrystal structure was determined in a single crystal diffraction experiment.
powder diffractionCrystal structure was determined in a powder diffraction experiment.
theoreticalCrystal structure was determined in a theoretical prediction either ab-initio or using any sort of prior data such as lattice constants and atomic composition.

_cod_struct_determination_method

Specifies what method (or class of methods) was used to determine the crystal structure.

Values:

ValueDescription
single crystalCrystal structure was determined in a single crystal diffraction experiment.
powder diffractionCrystal structure was determined in a powder diffraction experiment.
theoreticalCrystal structure was determined in a theoretical prediction either ab-initio or using any sort of prior data such as lattice constants and atomic composition.

COD_CHANGELOG_ENTRY

Data items from the COD_CHANGELOG_ENTRY are used to document changes made to the Crystallography Open Database entry.

_cod_changelog_entry_id

Value is a unique key to a set of COD_CHANGELOG_ENTRY items in a looped list.

_cod_changelog_entry_author

A string that identifies the person or software that changed the entry.

_cod_changelog_entry_date

The changelog entry creation timestamp expressed as a date-time or a full-date production of RFC3339 ABNF. Date-time production is preferred.

_cod_changelog_entry_text

A human-readable description of the change that was made.

COD_DEPOSITOR

The CATEGORY of data items used to store the information related to the depositor of the data.

Examples:

ValueDescription
_cod_depositor_requested_release_date 2020-12-20 The depositor has requested that the entry would not be released into the public domain until 2020-12-20.

_cod_depositor_requested_release_date

Specifies the date after which the data can be released into the public domain. Prior to the public release the given data is treated as confidential prepublication material.

_cod_hold_until_date

Specifies the date after which the data can be released into the public domain. Prior to the public release the given data is treated as confidential prepublication material.

_cod_depositor_comments

This data item is considered deprecated and is only retained in this dictionary for compatibility purposes. Data items from the COD_CHANGELOG_ENTRY and COD_ENTRY_ISSUE categories should be used instead.

Human readable comments from COD depositors and human readable log records from CIF processing programs.

Examples:

ValueDescription

The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed
to 'monoclinic' according to
'/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1
from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1468 2010-11-05 11:02:30Z adriana
Example based on COD entry 2000017, revision 176759. svn://www.crystallography.net/cod/cif/2/00/00/2000017.cif@176759 [http://www.crystallography.net/cod/2000017.cif@176759](http://www.crystallography.net/cod/2000017.cif@176759)

The H-M space group name 'A 1 1 2/a' in the original CIF
seems to be wrong, it is incompatible with the 'b axis
unique' comment. The b axis unique symbol should be
'A 1 2/a 1'. Encifer shows better packing when
H-M symbol is changed to 'A 1 2/a 1'

Saulius Gražulis
Example based on COD entry 2000154, revision 176343. svn://www.crystallography.net/cod/cif/2/00/01/2000154.cif@176343 [http://www.crystallography.net/cod/2000154.cif@176343](http://www.crystallography.net/cod/2000154.cif@176343)

COD_ENTRY_ISSUE

Data items from the COD_ENTRY_ISSUE category record issues pertaining to a specific COD entry. A proper issue record should include a human-readable description and assigned an appropriate severity level.

Examples:

ValueDescription

loop_
_cod_entry_issue_id
_cod_entry_issue_origin
_cod_entry_issue_severity
_cod_entry_issue_description
_cod_entry_issue_author
_cod_entry_issue_date
1 original note
;
  Anisotropic parameter values were not provided in the
  original publication.
;
'John Doe' 2010-07-15
2 upstream warning
;
  The declared distance between atoms 'C1' and 'O2' does not match
  the one calculated from the atomic coordinates.
;
An example of the COD_ENTRY_ISSUE loop that showcases all of the data items from the category.

_cod_entry_issue_id

Value is a unique key to a set of COD_ENTRY_ISSUE items in a looped list.

_cod_entry_issue_origin

The most original source that is known to be affected by the described issue.

Values:

ValueDescription
depositionIssue was introduced at the stage of structure deposition to the COD.
upstreamIssue can be traced back to an intermediate source such as a website, review publication, scientific database, etc. from which data in the COD was obtained.
originalIssue can be traced back to the original publication and there is no clear indication that the experiment itself was performed incorrectly.
experimentIssue can be traced back to the experiment itself.

_cod_entry_issue_severity

The severity level of the detected issue.

Values:

ValueDescription
noteIssue provides additional commentary on the data. The comments may describe interesting features that resulted from the original experiment as well as justify some of the straightforward changes applied during the data curation process. Issues of this severity level can generally be safely ignored.
warningIssue describes unusual data features that were not properly addressed by the original publication. The description may refer to the unresolved data inconsistencies as well as the best-effort solutions applied by the data maintainers. Issues of this severity level should be taken into account when using the data.
errorIssue describes serious data defects. Issues of this severity level usually signal that the affected dataset is not suitable for most applications.
retractionIssue provides clarification on why the structure was retracted from the COD.

_cod_entry_issue_description

A human-readable description of the issue.

Examples:

ValueDescription

The reported bond distances/angles involving atoms 'O4' and 'O11' do not
match the ones calculated from the given coordinates.
Crystallographic data in COD entry 2107238 exhibit unusual features described by the example issue text. Example based on COD entry 2107238, revision 189123. svn://www.crystallography.net/cod/cif/2/10/72/2107238.cif@189123 [http://www.crystallography.net/cod/2107238.cif@189123](http://www.crystallography.net/cod/2107238.cif@189123)

This entry is one of the GNU Xtal software test files. It describes a
hypothetical structure in an awkward high symmetry.
Crystallographic data in COD entry 1100919 exhibit unusual features described by the example issue text. Example based on COD entry 1100919, revision 208252. svn://www.crystallography.net/cod/cif/1/10/09/1100919.cif@208252 [http://www.crystallography.net/cod/1100919.cif@208252](http://www.crystallography.net/cod/1100919.cif@208252)

_cod_entry_issue_author

A string that identifies the person who described the issue.

_cod_entry_issue_date

The issue description creation timestamp expressed as a date-time or a full-date production of RFC3339 ABNF. Date-time production is preferred.