Crystallographic Information Framework

[CIF logo]

Index

Core dictionary (coreCIF) version 2.4.5

_geom_hbond_site_symmetry_

Names:
'_geom_hbond_site_symmetry_D' '_geom_hbond_site_symmetry_H' '_geom_hbond_site_symmetry_A'

Definition:

   The symmetry code of each atom site as the symmetry-equivalent
   position number 'n' and the cell translation number 'klm'.
   These numbers are combined to form the code 'n klm' or n_klm.
   The character string n_klm is composed as follows:

   n refers to the symmetry operation that is applied to the
   coordinates stored in _atom_site_fract_x, _atom_site_fract_y
   and _atom_site_fract_z. It must match a number given in
   _space_group_symop_id.

   k, l and m refer to the translations that are subsequently
   applied to the symmetry-transformed coordinates to generate
   the atom used in calculating the hydrogen bond. These
   translations (x,y,z) are related to (k,l,m) by the relations
        k = 5 + x
        l = 5 + y
        m = 5 + z
   By adding 5 to the translations, the use of negative numbers
   is avoided.

Examples:

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

Appears in list containing _geom_hbond_atom_site_label_

Type: char

Category: geom_hbond