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Index

Modulated and composite structures dictionary (msCIF) version 1.0.1

Category SPACE_GROUP_SYMOP

Name:
'_space_group_symop_[ms]'

Definition:

   The SPACE_GROUP_SYMOP category introduced in the symmetry CIF
   dictionary (cif_sym.dic) is intended to replace the original
   core SYMMETRY_EQUIV category. It contains information about the
   symmetry operations of the space group. For modulated structures,
   superspace-group descriptions may be included in the same
   category, but include the _ssg_ flag to indicate their
   dimensionality of > 3.

Example:

Example 1 - example corresponding to the one-dimensional incommensurately modulated structure of K~2~SeO~4~. 
 
    loop_
        _space_group_symop_ssg_id
        _space_group_symop_ssg_operation_algebraic
                1                       x1,x2,x3,x4
                2                       1/2+x1,1/2-x2,1/2-x3,x4
                3                       1/2-x1,1/2+x2,-x3,1/2-x4
                4                       -x1,-x2,1/2+x3,1/2-x4
                5                       -x1,-x2,-x3,-x4
                6                       1/2-x1,1/2+x2,1/2+x3,-x4
                7                       1/2+x1,1/2-x2,x3,1/2+x4
                8                       x1,x2,1/2-x3,1/2+x4


Type: null

Category: category_overview


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.