Dear all, I am working currently on a structure that should be "peptide bond" between chains, but the "second" part of the chain is in a symmetry related peer. Numbering is continuous and there are justifications to why the chains are separately named with different chain ID's. By the way, this "connection" is "full of glycines" so a kind of flexible, but a continuous stretch can be seen at "reasonable" density (and despite low resolution). To better explain, say I have chain C residue x to be bound to chain K, at symm operation -x-1,y-1/2,-z-1/2, residue x + 1. I would prefer to really refine the presence of these "connecting" glycines, of course with due geometrical restraints imposed (precious at this low resolution). phenix.refine offers: refinement.geometry_restraints.edits at bond with the possibility to indicate the symmetry_operation for the "second atom" within the bond. But this "symmetry_operation" indication is not available (?) for the other geometry_restraints edits, like angle, dihedral, etc. (eventually, planarity might also make easier). Do I miss anything here? Currently, I see 3 possibilities: a) somehow (how?) I can add angle, dihedral restraints in involving chains in symmetry related operations b) I bring the symmetry related chain to its non "symmetry related" position and change chains names/residues ID, etc., so I go into this go/return of naming at each step of the refinement work/analysis c) I add "extra" ( + - like alternate conformation residues) residues to each end of the connection, such that these extra residues will receive due conventional geometrical restraints (as phenix.refine does for contiguous residues in a chain) but I force them to be on the same position (and probably declare 0.5 occupancy for these overlying residues). "a" should be the easiest, if available somehow; "b" would be cumbersome during the refinement/analysis process; "c" seems to be the most complex but maybe the best if it works. Nevertheless, someone might have an easier suggestion. Thanks, Jorge