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Core CIF Dictionary version 2.3

_atom_site_aniso_U_

Names

'_atom_site_aniso_U_11' '_atom_site_aniso_U_12' '_atom_site_aniso_U_13' '_atom_site_aniso_U_22' '_atom_site_aniso_U_23' '_atom_site_aniso_U_33'

Category: atom_site

Data type: numb (with optional s.u. in parentheses)

Must appear in a looped list containing '_atom_site_aniso_label'

Related item: '_atom_site_aniso_B_'
Related function: conversion

Units: A^2^ ( angstroms squared)

Definition

    	
   These are the standard anisotropic atomic displacement
   components in angstroms squared which appear in the
   structure factor term:

   T = exp{-2pi^2^ sum~i~ [sum~j~ (U^ij^ h~i~ h~j~ a*~i~ a*~j~) ] }

   h = the Miller indices
   a* = the reciprocal-space cell lengths

   The unique elements of the real symmetric matrix are
   entered by row.
 


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