Data type: numb (with optional s.u. in parentheses)
Must appear in a looped list containing '_atom_site_label'
Enumeration range: 0.0 -> infinity
'_atom_site_B_iso_or_equiv' alternate '_atom_site_U_equiv_geom_mean' conversion
Units: A^2^ ( angstroms squared)
Equivalent isotropic atomic displacement parameter, B(equiv), in angstroms squared, calculated as the geometric mean of the anisotropic atomic displacement parameters. B(equiv) = (B~i~ B~j~ B~k~)^1/3^ B~n~ = the principal components of the orthogonalised B^ij^ The IUCr Commission on Nomenclature recommends against the use of B for reporting atomic displacement parameters. U, being directly proportional to B, is preferred.