get the twin law and either refine with phenix.refine twin_law="-h,-k,l" or whatever it suggests, or just add into your Refmac script the line TWIN and it will figure out the twin law for you.
You can also detwin data but then you might be throwing away a lot of data. We've now had two cases with twin fractions close to 49% and they can definitely not be refined in a higher symmetry space group. One was P21 the other I222.
Jürgen
On Mar 26, 2013, at 10:45 AM, Liang Zhang wrote:
Hi, All,
I got a set of P2(or P21) data for MR. However, the Phenix-Xtriage indicated that it could be a pseudo-merohedral twinning. Does anyone know how to deal with such kind of twinning problem? Thanks.
Best,
Liang
...................... Jürgen Bosch Johns Hopkins University Bloomberg School of Public Health Department of Biochemistry & Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Office: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-2926 http://lupo.jhsph.edu