Hello, I am trying to refine a surface cys that is alkylated by beta-mercaptoethanol (BME). The BME appears to have two poses and I am having trouble with getting phenix to understand the restraints. When I give the BME two conformations I get the error: Sorry: No atom selected: "chain A and resname ABME and resid 165 and name S2" My link_params file looks like this: refinement.geometry_restraints.edits { drgA_selection1 = chain A and resname ABME and resid 165 and name S2 bond { action = *add atom_selection_1 = $drgA_selection1 atom_selection_2 = $cys215_selection distance_ideal = 2.05 sigma = 0.02 slack = None } Not calling it ABME of course results in a non-unique atom error. Thanks for your help. Matthew Merski UCSF Shoichet Group