Index

Core dictionary version 3.0.14

_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.

Type: Real

Units: angstrom_squared

Category:
atom_site