Index

Core dictionary (coreCIF) version 2.4

_atom_site_U_iso_or_equiv

Definition:

   Isotropic atomic displacement parameter, or equivalent isotropic
   atomic  displacement parameter, U(equiv), in angstroms squared,
   calculated from anisotropic atomic displacement  parameters.

   U(equiv) = (1/3) sum~i~[sum~j~(U^ij^ a*~i~ a*~j~ a~i~ a~j~)]

   a     = the real-space cell lengths
   a*    = the reciprocal-space cell lengths

   Ref: Fischer, R. X. & Tillmanns, E. (1988). Acta Cryst. C44,
        775-776.

Appears in list containing _atom_site_label
The permitted range is 0.0 -> infinity

Related items : _atom_site_U_equiv_geom_mean (alternate)
_atom_site_B_iso_or_equiv (conversion)

Type: numb

Category: atom_site