Dear Dr. Adams, and/or other Phenix experts, I have done water-picking in CNS and some refinement in Refmac-5 in ccp4 and subsequent manual adjustments of waters in Coot and O. I have discovered that CNS seems to like the format 'OH2 TIP' for listing waters, whereas refmac only likes HOH. When I then run Auto_Build in the Phenix GUI, I get the following error message: Input failed Sorry, the PDB file /path/filename.pdb has an incomplete residue (or conformer/residue combination) in conformer ' ' chain S residue HOH 733 because the conformer is missing the following main chain atoms: [ 'N', 'CA', 'C' ]. The first water in my pdb file is indeed the one in question above. Apparently Phenix is thinking that this water should be a protein residue instead of solvent. Can anyone help me with this and tell me what I need to edit in the pdb file so that Phenix recognizes it as solvent instead of protein, or do I need to delete all waters and repick them in Phenix. I have tried changing the segid to from A to S with no success. Many Thanks, Jeff B.