That gap isnt surprising given your resolution - indeed anything smaller
could be suspicious! eg symmetry equivalent reflections labeled
differently..
Eleanor
On 12/10/2010 11:17 AM, Petr Kolenko wrote:
> Dear colleagues,
>
> I appreciate any help, or any suggestion with my difficult data. Many
> thanks at least for consideration.
> I work with datasets at 3.6AA of resolution. Integrated with XDS,
> scaled with SCALA. After integration and scaling in P1, POINTLESS
> suggested space group I432:
>
> Space group confidence: 0.95
> Laue group confidence: 1.000
> Total probability: 0.97
>
>
> After any longer refinement (more than 20 cycles), there was always a
> big gap between Rwork and Rfree (0.22 and 0.33), although the
> structure looks quite good at this resolution. I tried also space
> group I23, here are my statistics:
>
> Data processing (I23 vs I432):
> Rmerge - 0.124 vs 0.134
> high resolution Rmerge - 0.649 vs 0.732
> low resolution Rmerge - 0.048 vs 0.037
>
> The gap between Rwork and Rfree was stabilized in I23 using tight NCS
> restraints:
>
> Rwork vs Rfree:
> I23 withouth NCS: 0.228 vs 0.334
> I23 with NCS: 0.249 vs 0.296
> I43 : 0.228 vs 0.326
>
> My question is, what would you recommend me to close the gap? Or is
> this Rfree pointing out a lower real symmetry (I23) than suggested by
> POINTLESS or PHENIX.XTRIAGE (I432)? I have tried different selection
> of free reflections in I432 dataset already, but with almost the same
> results.
>
> Many thanks for any response.
> Petr
>
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