Pseudo translation doesnt seem too much of a problem if the model is OK.
MOLREP uses it within the search, phaser seems not to mind too much for
a general translation..
I dont know about pathological cases where the crystal is very near but
not quite C centred, ie the translation is quite special like in this
case with t = (1/2,0.~1/4)
On 02/09/2011 11:03 PM, Roberts, Sue A - (suer) wrote:
I have used phaser to successfully solve a structure in P2x2x2x that had
pseudo-translational symmetry. It was unable to correctly choose the space
group, but after running phaser in all 8 possible space groups and inspecting
the best solutions in each the correct solution was clear. Furthermore, it was
the only MR program that worked. Was I just lucky?
Sue
On 9 Feb 2011, at 22:27, Phil Jeffrey wrote:
Is there a program that does ? I was under the impression that they were all
equally good/bad at this, because any solution that agrees with the PTS has
quite a high score and any solution that doesn't has a low score, irrespective
of the correctness of the placement of the molecules.
In one case that ritually defeats me with quite strong pseudo-centering, this
seems to be true for heavy atom searches also.
Phil Jeffrey
Princeton
On 2/9/11 5:08 PM, Jon Schuermann wrote:
I would NOT use Phaser for MR with PTS present. It doesn't handle it
correctly yet, since the likelihood targets don't account for PTS.
Others may be able to explain it better.
Dr. Sue A. Roberts
Dept. of Chemistry and Biochemistry
University of Arizona
1041 E. Lowell St., Tucson, AZ 85721
Phone: 520 621 8171
s...@email.arizona.edu
http://www.biochem.arizona.edu/xray
