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Macromolecular dictionary (mmCIF) version 2.0.09

_atom_site.U_iso_or_equiv

Name:
'_atom_site.U_iso_or_equiv'

Definition:

   Isotropic atomic displacement parameter, or equivalent isotropic
   atomic  displacement parameter, U~eq~, calculated from
   anisotropic atomic displacement  parameters.

   U~eq~ = (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: float

Type conditions: esd

Mandatory item: no

Alias:
_atom_site_U_iso_or_equiv (cif_core.dic version 2.0.1)
The permitted range is [0.0, 10.0]

Related items: _atom_site.U_iso_or_equiv_esd (associated_esd)
_atom_site.B_iso_or_equiv (conversion_constant)

Category: atom_site