Crystallographic Information Framework

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Core dictionary version 3.0.14

_geom_angle.site_symmetry_3

Name:
_geom_angle.site_symmetry_3

Alias:
_geom_angle_site_symmetry_3

Definition:

   
     The set of data items which specify the symmetry operation codes
     which must be applied to the atom sites involved in the geometry angle.

     The symmetry code of each atom site as the symmetry-equivalent position
     number 'n' and the cell translation number 'pqr'. These numbers are
     combined to form the code 'n pqr' or n_pqr.

     The character string n_pqr is composed as follows:

     n refers to the symmetry operation that is applied to the
     coordinates stored in _atom_site.fract_xyz. It must match a
     number given in _symmetry_equiv.pos_site_id.

     p, q and r refer to the translations that are subsequently
     applied to the symmetry transformed coordinates to generate
     the atom used in calculating the angle. These translations
     (x,y,z) are related to (p,q,r) by the relations
          p = 5 + x
          q = 5 + y
          r = 5 + z

Examples:

4 4th symmetry operation applied
7_645 7th symm. posn.; +a on x; -b on y
. no symmetry or translation to site

Type: Symop

Category:
geom_angle