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
