Crystallographic Information Framework

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Index

Symmetry dictionary (symCIF) version 1.0.1

Category SPACE_GROUP_WYCKOFF

Name:
'space_group_Wyckoff'

Description:

   Contains 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.

Example:

Example 1 - this example is taken from the space group F d -3 c (No. 228, origin choice 2). For brevity only a selection of special positions are listed. The coordinates of only one site per special position can be given in this item, but the coordinates of the other sites can be generated using the symmetry operations given in the SPACE_GROUP_SYMOP category. 
     loop_
    _space_group_Wyckoff.id
    _space_group_Wyckoff.multiplicity
    _space_group_Wyckoff.letter
    _space_group_Wyckoff.site_symmetry
    _space_group_Wyckoff.coord_xyz
        1  192   h   1      x,y,z
        2   96   g   ..2    1/4,y,-y
        3   96   f   2..    x,1/8,1/8
        4   32   b   .32    1/4,1/4,1/4


Category key:
    _space_group_Wyckoff.id

Mandatory category: no


International Tables for Crystallography

Volume G: Definition and exchange of crystallographic data

First online edition (2006)

Edited by S. R. Hall and B. McMahon

An essential guide and reference to CIF for programmers, data managers handling crystal-structure information and practising crystallographers.