Index

Macromolecular dictionary (mmCIF) version 2.0.09

_refine_analyze.RG_free

Name:
'_refine_analyze.RG_free'

Definition:

   The Hamilton generalized R factor for all reflections that
   satisfy the resolution limits established by
   _refine_analyze.RG_d_res_high and
   _refine_analyze.RG_d_res_low for the free R set of
   reflections that were excluded from the refinement.

             sum_i sum_j w_{i,j}(|Fobs|_i - G|Fcalc|_i)(|Fobs|_j - G|Fcalc|_j)
 RG = Sqrt( ----------------------------------------------------------------- )
              sum_i sum_j w_{i,j} |Fobs|_i |Fobs|_j

   where

   |Fobs|  = the observed structure-factor amplitudes
   |Fcalc| = the calculated structure-factor amplitudes
   G       = the scale factor which puts |Fcalc| on the
             same scale as |Fobs|
   w_{i,j} = the weight for the combination of the reflections
             i and j.

   sum_i and sum_j are taken over the specified reflections

   When the covariance of the amplitudes of reflection i and
   reflection j is zero (i.e. the reflections are independent)
   w{i,i} can be redefined as  w_i and the nested sums collapsed
   into one sum.

               sum_i w_i(|Fobs|_i - G|Fcalc|_i)^2
   RG = Sqrt( ----------------------------------- )
                      sum_i w_i |Fobs|_i^2

   Ref: Hamilton, W. C. (1965). Acta Cryst. 18, 502-510.

Type: float

Mandatory item: no

Alias:
_refine_analyze.ebi_RG_free (ebi_extensions version 1.0)
The permitted range is [0.0, infinity)

Category: refine_analyze