Sam_rename [molecule] [res1 res2] [first_residue_name]
Change the residue name of a given zone of residues. Residue names are generated from the first residue name supplied. Entering A1, for example, generates names like A1, A2 etc. Suppose you have 2 molecules in the asymmetric unit and they have residue names in the ranges 1-200 and 201-400. The following commands may be used to call them molecules A and B with names in the range 1-200.
sam_rename m23 1 200 a1 sam_rename m23 201 400 b1