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Powder dictionary (pdCIF) version 1.0.1

Category PD_BLOCK

Name:
'_pd_block_[pd]'

Definition:

   _pd_block_id is used to assign a unique ID code to a data block.
   This code is then used for references between different blocks
   (see _pd_block_diffractogram_id, _pd_calib_std_external_block_id
   and _pd_phase_block_id).

   Note that a data block may contain only a single diffraction
   data set or information about a single crystalline phase. 
   However, a single diffraction measurement may yield structural 
   information on more than one phase, or a single structure 
   determination may use more than one data set. Alternatively, 
   results from a single data set, such as calibration parameters 
   from measurements of a standard, may be used for many subsequent 
   analyses. Through use of the ID code, a reference made between 
   data sets may be preserved when the file is exported from the 
   laboratory from which the CIF originated.

   The ID code assigned to each data block should be unique with
   respect to an ID code assigned for any other data block in the
   world. The naming scheme chosen for the block-ID format is
   designed to ensure uniqueness.

   It is the responsibility of a data archive site or local
   laboratory to create a catalogue of block IDs if that site
   wishes to resolve these references.

Type: null

Category: category_overview