Data Item _refine.pdbx_pd_Marquardt_correlation_coeff

General

Item name
_refine.pdbx_pd_Marquardt_correlation_coeff
Category name
refine
Attribute name
pdbx_pd_Marquardt_correlation_coeff
Required in PDB entries
no
Used in current PDB entries
Yes, in about 0.000 % of entries

Item Description

The correlation coefficient between the observed and calculated structure factors for reflections included in the refinement. This correlation factor is found in the fitting using the Levenberg-Marquardt algorithm to search for the minimum value of chisquare. Almost all computer codes for Rietveld refinement employ the Gauss-Newton algorithm to find parameters which minimize the weighted sum of squares of the residuals. A description of the equations is given on http://www.water.hut.fi/tkarvone/fr_org_s.htm

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]+)?