Data Item _refine.pdbx_average_fsc_free

General

Item name
_refine.pdbx_average_fsc_free
Category name
refine
Attribute name
pdbx_average_fsc_free
Required in PDB entries
no
Used in current PDB entries
Yes, in about 0.04 % of entries

Item Description

Average Fourier Shell Correlation (avgFSC) between model and observed structure factors for reflections not included in refinement. The average FSC is a measure of the agreement between observed and calculated structure factors. sum(Ni FSCfree-i) avgFSCfree = --------------------- sum(Ni) Ni = the number of free reflections in the resolution shell i FSCfree-i = FSC for free reflections in the i-th resolution shell calculated as: (sum(|Fo| |Fc| fom cos(phic-phio))) FSCfree-i = ------------------------------------------- (sum(|Fo|2) (sum(|Fc|2)))1/2 |Fo| = amplitude of observed structure factor |Fc| = amplitude of calculated structure factor phio = phase of observed structure factor phic = phase of calculated structure factor fom = figure of merit of the experimental phases. Summation of FSCfree-i is carried over all free reflections in the resolution shell. Summation of avgFSCfree is carried over all resolution shells. Ref: Rosenthal P.B., Henderson R. "Optimal determination of particle orientation, absolute hand, and contrast loss in single-particle electron cryomicroscopy. Journal of Molecular Biology. 2003;333(4):721-745, equation (A6).

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]+)?