Index

Protein Data Bank exchange dictionary (pdbx) version 1.0521

_pdbx_refine_component.density_index

Definition:

   
      The index of density is the product of the (2Fobs-Fcal) electron 
      density values for the group of atoms divided by the average value
      for the structure. Low values (less than 1.0) may be problematic for 
      model fitting.

      index = [(D(xi)...D(xi))^(1/N)] /<D>_all

      Where :
      D(xi) = (2*Fobs - Fcal)
      <D>_all is the averaged value of density for the structure.
      The product is for N atoms of group.

      Ref: Vaguine, A.A., Richelle, J. & Wodak, S.J. (1999). Acta Cryst. D55,199-205

Type: float

Mandatory item: no

Category: pdbx_refine_component