Data Item _refine.overall_FOM_free_R_set

General

Item name
_refine.overall_FOM_free_R_set
Category name
refine
Attribute name
overall_FOM_free_R_set
Required in PDB entries
no
Used in current PDB entries
Yes, in about 0.001 % of entries

Item Description

Average figure of merit of phases of reflections not included in the refinement. This value is derived from the likelihood function. FOM = I_1(X)/I_0(X) I_0, I_1 = zero- and first-order modified Bessel functions of the first kind X = sigma_A |E_o| |E_c|/SIGMA E_o, E_c = normalized observed and calculated structure factors sigma_A = <cos 2 pi s delta_x> SQRT(Sigma_P/Sigma_N) estimated using maximum likelihood Sigma_P = sum_{atoms in model} f2 Sigma_N = sum_{atoms in crystal} f2 f = form factor of atoms delta_x = expected error SIGMA = (sigma_{E;exp})2 + epsilon [1-(sigma_A)2] sigma_{E;exp} = uncertainties of normalized observed structure factors epsilon = multiplicity of the diffracting plane Ref: Murshudov, G. N., Vagin, A. A. & Dodson, E. J. (1997). Acta Cryst. D53, 240-255.

Data Type

Data type code
float
Data type detail
int 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]+)?

Aliases

Alias Item Name Dictionary Name Dictionary Version
_refine.ebi_overall_FOM_free_Rset ebi_extensions 1.0