Describes CIF, the data exchange standard of crystallography. Provides: information for scientists who wish to record or use the results of a single-crystal or powder diffraction experiment; the data ontology necessary for designing interoperable computer applications; accompanying software including machine-readable CIF dictionaries, libraries and utility programs.
An essential guide and reference to CIF for programmers, data managers handling crystal-structure information and practising crystallographers.
Residual factor R for reflections that satisfy the resolution limits established by _refine.ls_d_res_high and _refine.ls_d_res_low and the observation limit established by _reflns.observed_criterion. _refine.ls_R_factor_obs should not be confused with _refine.ls_R_factor_R_work; the former reports the results of a refinement in which all observed reflections were used, the latter a refinement in which a subset of the observed reflections were excluded from refinement for the calculation of a 'free' R factor. However, it would be meaningful to quote both values if a 'free' R factor were calculated for most of the refinement, but all of the observed reflections were used in the final rounds of refinement; such a protocol should be explained in _refine.details. sum|F~obs~ - F~calc~| R = --------------------- sum|F~obs~| F~obs~ = the observed structure-factor amplitudes F~calc~ = the calculated structure-factor amplitudes sum is taken over the specified reflections
Mandatory item: noAlias:
Related item: _refine.ls_wR_factor_obs (alternate)