On 10/19/2010 12:39 AM, Jyotica Batra wrote:
> Hi All
>
> I have a dataset at 1.9A, spacegroup-P212121 (unit cell: 37.7, 39.52, 231.72, 90, 90, 90),
> I used MR phaser and got a structure solution with LLG= 320 (1copy/a.u) . During refinement, the R-free (50%) and R-factors (42%) never go down.
> I have tried refining in phenix and refmac both, but still the high R-free problem persists. At this point I'm seeking help to know the possible reasons for this high R-free.
>
> Thanks in advance!
>
> Jyotica
>
>
Are you sure the mtz file has the correxct SG - after data integration
you can be pretty sure of the pointt group, P222 here, but it is harder
to decide the spacegroup P222 or P21 2 2 or .. P21 21 21.
Once you have a model in P212121 with that fantastic LLG, you need to be
sure you are refining is also in that SG.
If your mtz file has a different SG listed just use:
mtzutils hklin1 old.mtz hklout new.mtz
SYMM P212121
end
and refine against the new.mtz
Eleanor
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