Hi Phenix developers, I have an issue using 1.8.1 (1168) with excluding atoms from coordinate refinement. I have defined a certain residue to be excluded from coordinate refinement, as can be seen in the .eff file produced by this run. refine { strategy = *individual_sites individual_sites_real_space rigid_body \ *individual_adp group_adp *tls *occupancies group_anomalous sites { individual = not (resseq 60 and resname PHE) torsion_angles = not (resseq 60 and resname PHE) rigid_body = None ... However, this gets ignored, and this residue and its NCS-related brethren get moved into nondescript electron density on a symmetry axis. This residue was just fine in an earlier version of Phenix, but when I switched to 1.8.1, it started moving into this density. So, I thought excluding it from xyz refinement, which is a dirty trick in my opinion, would fix this problem. Not so. I have the feeling that this is due to rotamer corrections as part of the torsion NCS implemented in 1.8.1 now. Sticking a zero occupancy dummy atom in the density did prevent this residue from moving in. Turning off torsion NCS also fixed it. By the way, I have "fix rotamer sidechains" off, as I am yet to see it improve things (at medium or low resolution). Thanks and happy holidays! Engin