I started running this function and then realized that I probably need to do something to take the perfect twinning into account. I'm not sure of the best way to do this. I believe the map coefficients output by a run phenix.refine should be detwinned as I give a twin law when running phenix.refine. Should I detwin the mtz containing the data and then use those files for the multi crystal averaging? Is there a way to output detwinned data mtz files in phenix or do I need to use another program? Also, I have two ncs copies in the ASU. There's a region of density in both ncs copies that I'm trying to improve the maps for with the multi crystal averaging. I don't have anything built in the region yet. Is there a way to use the NCS and multi crystal averaging at the same time without any pdb coordinates in that region? Even with my goof up about the twinning, the eff script I created appeared to run without problems. Thanks, Mary X. Fitzgerald Postdoctoral Associate Arnold Lab