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Macromolecular dictionary (mmCIF) version 2.0.09

_reflns_class.R_Fsqd_factor

Name:
'_reflns_class.R_Fsqd_factor'

Definition:

   For each reflection class, the residual factor R(F^2^) calculated
   on the squared amplitudes of the observed and calculated
   structure factors for the reflections judged significantly
   intense (i.e. satisfying the threshold specified by
   _reflns.threshold_expression) and included in the refinement.

   The reflections also satisfy the resolution limits established
   by _reflns_class.d_res_high and _reflns_class.d_res_low.

              sum | F(obs)^2^ - F(calc)^2^ |
   R(Fsqd) = -------------------------------
                      sum F(obs)^2^

   F(obs)^2^  = squares of the observed structure-factor amplitudes
   F(calc)^2^ = squares of the calculated structure-factor
                amplitudes

   and the sum is taken over the reflections of this class.

Type: float

Mandatory item: no

Alias:
_reflns_class_R_Fsqd_factor (cif_core.dic version 2.3)
The permitted range is [0.0, infinity)

Category: reflns_class