I second that. Incorrect space group assignment usually causes this
behaviour of having R and R-free stuck at very high values. It is useful
to go back to the data processing stage and carefully consider all
Bravais lattices (and associated space groups) that the autoindexing
routine finds consistent with your diffraction data frames.
Fred.
Jim Fairman wrote:
Did you check your data for twinning and/or pseudo symmetry using
phenix.xtriage or Pointless? If the space group is incorrect, these
programs will also assist you in selecting the correct one. What were
the Z-scores for the rotation and translation functions?
On Mon, Oct 18, 2010 at 7:39 PM, Jyotica Batra <batra.jyot...@mayo.edu
<mailto:batra.jyot...@mayo.edu>> 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
--
Jim Fairman, Ph D.
Post-Doctoral Fellow
National Institutes of Health - NIDDK
Lab: 1-301-594-9229
E-mail: fairman....@gmail.com <mailto:fairman....@gmail.com>
james.fair...@nih.gov <mailto:james.fair...@nih.gov>
