Data Item _refine.ls_abs_structure_Flack

General

Item name
_refine.ls_abs_structure_Flack
Category name
refine
Attribute name
ls_abs_structure_Flack
Required in PDB entries
no
Used in currrent PDB entries
No

Item Description

The measure of absolute structure (enantiomorph or polarity) as defined by Flack (1983). For centrosymmetric structures, the only permitted value, if the data name is present, is 'inapplicable', represented by '.' . For noncentrosymmetric structures the value must lie in the 99.97% Gaussian confidence interval -3u =< x =< 1 + 3u and a standard uncertainty (estimated standard deviation) u must be supplied. The item range of [0.0:1.0] is correctly interpreted as meaning (0.0 - 3u) =< x =< (1.0 + 3u). Ref: Flack, H. D. (1983). Acta Cryst. A39, 876-881.

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]+)?

Allowed Boundary Conditions

Minimum Value Maximum Value
0.0 1.0

Aliases

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