Index

Core dictionary version 3.3.0

_atom_site.site_symmetry_multiplicity

Definition:

   
    The number of different sites that are generated by the
    application of the space-group symmetry to the coordinates
    given for this site. It is equal to the multiplicity given
    for this Wyckoff site in International Tables for Crystallography
    Vol. A (2016). It is equal to the multiplicity of the general
    position divided by the order of the site symmetry given in
    _atom_site.site_symmetry_order.

    The _atom_site_symmetry_multiplicity form of this data name is
    deprecated because of historical inconsistencies in practice among
    structure refinement software packages and should not be used.

    Reference: International Tables for Crystallography (2016). Volume A,
     Space-group symmetry, edited by M. I. Aroyo, 6th ed.
     Chichester: John Wiley & Sons.

Type: Integer

Units: none

Evaluation method:

     With  a  as  atom_site

        mul  =   0
        xyz  =   a.fract_xyz

          Loop  s  as  space_group_symop  {
             sxyz  =   s.R * xyz + s.T
             diff  =   Mod( 99.5 + xyz - sxyz, 1.0) - 0.5
             If ( Norm ( diff ) < 0.1 ) mul +=  1
       }
    _atom_site.site_symmetry_multiplicity =  _space_group.multiplicity / mul

Category:
atom_site