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Macromolecular dictionary (mmCIF) version 2.0.09




   The least-squares goodness-of-fit parameter S for reflection data
   classified as 'observed' (see _reflns.observed_criterion) after
   the final cycle of refinement. Ideally, account should be taken
   of parameters restrained in the least-squares refinement.
   See also the definition of _refine.ls_restrained_S_obs.

       ( sum|w |Y~obs~ - Y~calc~|^2^| )^1/2^
   S = ( ---------------------------- )
       (       N~ref~ - N~param~      )

   Y~obs~   = the observed coefficients
              (see _refine.ls_structure_factor_coef)
   Y~calc~  = the calculated coefficients
              (see _refine.ls_structure_factor_coef)
   w        = the least-squares reflection weight
              [1/(e.s.d. squared)]

   N~ref~   = the number of reflections used in the refinement
   N~param~ = the number of refined parameters

   sum is taken over the specified reflections

Type: float

Type conditions: esd

Mandatory item: no

_refine_ls_goodness_of_fit_obs (cif_core.dic version 2.0.1)
The permitted range is [0.0, infinity)

Related item: _refine.ls_goodness_of_fit_obs_esd (associated_esd)

Category: refine