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Core CIF Dictionary version 2.3

_refine_ls_class_R_Fsqd_factor

Name

'_refine_ls_class_R_Fsqd_factor'

Category: refine_ls_class

Data type: numb

Must appear in a looped list containing '_refine_ls_class_code'

Enumeration range: 0.0 -> infinity

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 _refine_ls_class_d_res_high and _refine_ls_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.
 


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