On Mon, Sep 26, 2011 at 6:29 PM, Yuri wrote:

I have a twinned data set with PM twin operator h,-k,-h-l I was able to input the twin law into the refinement parameters, however I do not see a place that asks me for the law when generating the Rfree flags. Could someone point me in the right direction?

The default behavior in Phenix is to use the highest possible lattice symmetry to generate R-free flags, and then expand to lower symmetry if necessary. This should ensure that the twinned refinement does not bias the R-free. All it needs to do this is the symmetry information - the twin operator is irrelevant when generating flags. -Nat