Hi all, I am encountering a strange crash when running phenix.refine through the command line with reference model restraints turned on. The references point to two different PDB files, one labeled as chain A and one labeled as chain B. This error occurs whether I have my refinement model in P1 with 192 chains or P2(1) with 96 chains. The chains are A-EZ (192) or A-BH (96). It appears to fail to align the reference models to the sequences in the refinement model. This error does not occur with other smaller target structures under 25 chains and reference models used with the same installation of phenix. I am hoping for any advice on why this might be happening or how I might get around it. ================== Extract refinement strategy and selections ================= Refinement flags and selection counts: individual_sites = True (401472 atoms) torsion_angles = False (0 atoms) rigid_body = True (401472 atoms in 192 groups) individual_adp = False (iso = 0 aniso = 0) group_adp = True (201984 atoms in 25824 groups) tls = False (0 atoms in 0 groups) occupancies = False (0 atoms) group_anomalous = False n_use = 401472 n_use_u_iso = 401472 n_use_u_aniso = 0 n_grad_site = 0 n_grad_u_iso = 0 n_grad_u_aniso = 0 n_grad_occupancy = 0 n_grad_fp = 0 n_grad_fdp = 0 total number of scatterers = 401472 *** Adding Reference Model Restraints *** determining reference matches automatically... Traceback (most recent call last): File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/build/intel-linux-2.6-x86_64/../../phenix/phenix/command_line/refine.py", line 11, in <module> command_line.run(command_name="phenix.refine", args=sys.argv[1:]) File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/phenix/phenix/refinement/command_line.py", line 92, in run master_params=customized_master_params) File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/phenix/phenix/refinement/driver.py", line 501, in __init__ log=self.log) File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/cctbx_project/mmtbx/torsion_restraints/reference_model.py", line 147, in __init__ self.get_reference_dihedral_proxies() File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/cctbx_project/mmtbx/torsion_restraints/reference_model.py", line 460, in get_reference_dihedral_proxies log=self.log) File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/cctbx_project/mmtbx/torsion_restraints/reference_model.py", line 323, in process_reference_groups moving_chain = mod_h) File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/cctbx_project/mmtbx/torsion_restraints/utils.py", line 426, in _ssm_align ssm_alignment = ccp4io_adaptbx.SSMAlignment.residue_groups(match=ssm) File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/ccp4io_adaptbx/__init__.py", line 215, in residue_groups return cls( match = match, indexer = indexer ) File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/ccp4io_adaptbx/__init__.py", line 176, in __init__ self.pairs.append( ( get( f, indexer1 ), get( s, indexer2 ) ) ) File "/auto_nfs/joule2/programs/phenix/phenix-installer-dev-1457/phenix-dev-1457/ccp4io_adaptbx/__init__.py", line 173, in get assert identifier in indexer, "Id %s missing" % str( identifier ) AssertionError: Id ('A', 1, ' ') missing Best, Dan