Dear Phenix developers, I'm working with pseudo-merohedrally twinned data (fraction 45%), using Phenix-dev-616. I have three questions about phenix.refine with twin_law. (running on the command line) During refinement with twin_law, the log file says x-ray target function is set to "twin_lsq_f". Does it mean, we cannot use maximum likelihood target for twinned data? If so, is it recommended to refine without twin_law at first several cycles? When I tried to refine using the model refined without twin_law, the target function was still ml, not twin_lsq_f although I specified twin_law. Is this a bug? When I used twin_law option, in the table "R-free likelihood based estimates", "Scale factor" were None in all resolution bins. Cannot scale factor be calculated during twin refinement? Thanks in advance and Wishing you the best holidays, Keitaro