Hi all, I'm having an issue during structure refinement where I can't seem to get my Rfree to drop below about 0.30 (whereas Rwork is around 0.24) and was wondering if anyone had any thoughts on the matter. I have a 2.3Å dataset that I processed the data in P31 and got an MR solution in phaser with RFZ=29.3, TFZ=14.9. There is 6-fold NCS present in the structure and it appears there is pseudotranslational symmetry with P62 as well. I have run Zanuda and P31 seems to be the correct space group. Also, Xtriage didn't detect any sort of twinning. Before refinement in phenix the R/Rfree gap is rather small, however even after one round of refinement I am finding that this gap increases to almost 0.06. I have a feeling that the high symmetry present has something to with this R/Rfree gap but was hoping some of you may have some helpful suggestions for how to deal with it.
Thanks, Kim
