The value of _diffrn_reflns_av_R_equivalents should normally be
considerably less than 0.10. Higher values should be accompanied by
a suitable explanation in the _publ_section_exptl_refinement section.
However, authors should first ensure that there are not overlooked
problems associated with the data or the space group. Elevated
values for _diffrn_reflns_av_R_equivalents may be indicative of a
need to recollect the data from a crystal of higher quality or that
there is a problem with the data treatment. Consider the following:
(a) The absorption corrections are inadequate or inappropriate.
(b) The overall quality of the data may be poor due to the crystal quality.
(c) The crystal is very weakly diffracting, so that a large proportion of essentially "unobserved" reflections are being used in the refinement. You should consider using a better crystal or a data collection at low temperature and/or, if the compound is organic, using Cu radiation. (d) You are working in the wrong crystal system or Laue group.
(e) You have only a very small number of equivalent reflections, which may lead to artificially high values of _diffrn_reflns_av_R_equivalents
Note that if _diffrn_reflns_av_sigmaI/netI is also large, the quality of the data should be considered to be suspect.
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