Modulated Structures CIF Dictionary version 1.0

_audit_link_[ms]

Name

Category: category_overview

Data type: null

Examples:

    loop_
    _audit_link_block_code
    _audit_link_block_description
       .               'publication details'
       K2SEO4_COM      'experimental data common to ref./mod. structures'
       K2SEO4_REFRNCE  'reference structure'
       K2SEO4_MOD      'modulated structure'

Example 1 - example file for the one-dimensional incommensurately modulated structure of K~2~SeO~4~.

    _audit_link_block_code      'PbSVS2_MOD_VS2'

Example 2 - example with a trailing string referencing a modulated structure of the subsystem labelled by _cell_subsystem_code.

Definition

    	
   This category description does NOT introduce a new category;
   instead, it describes the recommended practice for using
   block codes as described in the core AUDIT_LINK category for
   descriptions of modulated structures.

   The value of audit_block_code may be associated with a data
   block in the same or a different file related to the current
   data block. For an appropriate use of this item,
   audit_block_code should be unique.

   A recommended way for naming data blocks is the following:

           <string>         For the data block that includes those items that,
                given a certain material, are independent of a
                specific structure (modulated, reference, etc.).
                Consider, for example, the experimental set-up,
                publication details, etc.

           <string>_REFRNCE For the data block that contains specific details
                corresponding to the reference (unmodulated)
                structure if it was refined separately using only
                main reflections. In the case of composites this
                data block may gather those items that are common
                to the reference structures of all subsystems.

           <string>_MOD     For the data block where specific details concerning
                the modulated structure are defined. Again, in the
                case of composites this data block may include
                either those items that are common to the modulated
                structures of all subsystems or the whole modulated
                structure if it is described implicitly through the
                *_subsystem_code pointers.

   A trailing code following the reserved words MOD or REFRNCE
   would indicate that the corresponding data block includes
   structural information corresponding to the modulated or
   reference structures of the subsystem labelled by
   _cell_subsystem_code. A good format for <string> can be found
   in the definitions of _pd_block_[pd] and _pd_block_id that
   belong to the dictionary extension cif_pd.dic
   (http://www.iucr.org/cif/pd/index.html).