Data Item _atom_site.U_iso_or_equiv

General

Item name
_atom_site.U_iso_or_equiv
Category name
atom_site
Attribute name
U_iso_or_equiv
Required in PDB entries
no
Used in currrent PDB entries
No

Item Description

Isotropic atomic displacement parameter, or equivalent isotropic atomic displacement parameter, Ueq, calculated from anisotropic atomic displacement parameters. Ueq = (1/3) sumi[sumj(Uij Ai Aj 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.

Data Type

Data type code
float
Data type detail
float item types are the subset of numbers that are the floating numbers.
Primitive data type code
numb
Regular expression
-?(([0-9]+)[.]?|([0-9]*[.][0-9]+))([(][0-9]+[)])?([eE][+-]?[0-9]+)?
Units
angstroms_squared

Allowed Boundary Conditions

Minimum Value Maximum Value
0.0 10.0

Aliases

Alias Item Name Dictionary Name Dictionary Version
_atom_site_U_iso_or_equiv cif_core.dic 2.0.1