Data Item _refine.pdbx_density_correlation


Item name
Category name
Attribute name
Required in PDB entries
Used in currrent PDB entries

Item Description

The density correlation coefficient is calculated from atomic densities of (2Fobs-Fcalc) map - "Robs" and the model map (Fcalc) - "Rcalc" : D_corr = <Robs><Rcalc>/sqrt(<Robs**2><Rcalc**2>) where <Robs> is the mean of "observed" densities of all atoms <Rcalc> is the mean of "calculated" densities of all atoms. The value of density for some atom from map R(x) is: sum_i ( R(xi) * Ratom(xi - xa) ) Dens = ---------------------------------- sum_i ( Ratom(xi - xa) ) where Ratom(x) is atomic electron density for the x-th grid point. xa - vector of the centre of atom. xi - vector of the i-th point of grid. Sum is taken over all grid points which have distance from the center of the atom less than the Radius_limit. For all atoms Radius_limit = 2.5 A. Ref: Vaguine, A.A., Richelle, J. & Wodak, S.J. (1999). Acta Cryst. D55,199-205

Data Type

Data type code
Data type detail
float item types are the subset of numbers that are the floating numbers.
Primitive data type code
Regular expression