Data Item _atom_site.aniso_B[2][2]

General

Item name
_atom_site.aniso_B[2][2]
Category name
atom_site
Attribute name
aniso_B[2][2]
Required in PDB entries
no
Used in currrent PDB entries
No

Item Description

The [2][2] element of the anisotropic atomic displacement matrix B, which appears in the structure-factor term as: T = exp{-1/4 sumi[sumj(Bij hi hj a*i a*j)]} h = the Miller indices a* = the reciprocal space cell lengths These matrix elements may appear with atomic coordinates in the ATOM_SITE category, or they may appear in the separate ATOM_SITE_ANISOTROP category, but they may not appear in both places. Similarly, anisotropic displacements may appear as either B's or U's, but not as both. The unique elements of the real symmetric matrix are entered by row. The IUCr Commission on Nomenclature recommends against the use of B for reporting atomic displacement parameters. U, being directly proportional to B, is preferred.

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
8pi2_angstroms_squared

Subcategories

Subcategory Name Subcategory Description
matrix The collection of elements of a matrix.