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Core CIF Dictionary version 2.3




Category: refine

Data type: numb

Enumeration range: 0.0 -> infinity


   Residual factor R(Fsqd), calculated on the squared amplitudes
   of the observed and calculated structure factors, for
   significantly intense reflections (satisfying
   _reflns_threshold_expression) and included in the refinement.

   The reflections also satisfy the resolution limits established
   by _refine_ls_d_res_high and _refine_ls_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

   and the sum is taken over the specified reflections

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