Modulated Structures CIF Dictionary version 1.0

_space_group_symop_[ms]

Name

Category: category_overview

Data type: null

Examples:

    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

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

Definition

    	
   The SPACE_GROUP_SYMOP category introduced in the Symmetry Cif
   dictionary (cif_sym.dic 1.0) 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.