Hi, I got the following error when I added a NAG-ASN link in the def file. /nfs/home/jzhu/xiao/x61b/phenix6/temp/x61b.pdb Monomer Library directory: "/nfs/home/jzhu/phenix-1.3b-rc3/ext_ref_files/mon_lib" Total number of atoms: 46651 apply_cif_link: data_link: NAG-ASN mod_id_1: DEL-O1 mod_id_2: DEL-HD22 residue_selection_1: chain S and resname NAG and resid 1001 residue_selection_2: chain A and resname ASN and resid 15 Number of models: 1 Model: 0 Number of conformers: 1 Conformer: " " Number of atoms: 46651 Number of chains: 8 Number of residues, atoms: 909, 13713 Unexpected atoms: {'ASN%DEL-HD22,HD22': 1} Classifications: {'peptide': 909} Modifications used: {'DEL-HD22': 1, 'NH3': 1} Link IDs: {'PTRANS': 59, 'TRANS': 847, 'PCIS': 2} Chain breaks: 3 Number of residues, atoms: 601, 8947 Classifications: {'peptide': 601} Modifications used: {'NH3': 1} Link IDs: {'PTRANS': 28, 'TRANS': 569, 'PCIS': 3} Chain breaks: 2 Number of residues, atoms: 898, 13559 Classifications: {'peptide': 898} Modifications used: {'NH3': 1} Link IDs: {'PTRANS': 59, 'TRANS': 836, 'PCIS': 2} Chain breaks: 3 Number of residues, atoms: 602, 8954 Classifications: {'peptide': 602} Modifications used: {'NH3': 1} Link IDs: {'PTRANS': 28, 'TRANS': 570, 'PCIS': 3} Chain breaks: 2 Number of residues, atoms: 642, 642 Classifications: {'water': 642} Link IDs: {None: 641} Number of residues, atoms: 31, 780 Unusual residues: {'MAN': 7, 'NAG%DEL-O1': 1, 'NAG': 23} Classifications: {'undetermined': 31} Modifications used: {'DEL-O1': 1} Link IDs: {None: 30, 'NAG-ASN': 1} Unresolved non-hydrogen bonds: 30 Unresolved non-hydrogen angles: 60 Unresolved non-hydrogen chiralities: 30 Number of residues, atoms: 16, 16 Unusual residues: {' MG': 2, ' CA': 14} Classifications: {'undetermined': 16} Link IDs: {None: 15} Number of residues, atoms: 4, 40 Unusual residues: {'IMD': 4} Classifications: {'undetermined': 4} Link IDs: {None: 3} Number of atoms with unknown nonbonded energy type symbols: 1 "HD22 ASN A 15 " Time building chain proxies: 32.54, per 1000 atoms: 0.70 Sorry: Fatal problems interpreting PDB file: Number of atoms with unknown nonbonded energy type symbols: 1 Please edit the PDB file to resolve the problems and/or supply a CIF file with matching restraint definitions, along with apply_cif_modification and apply_cif_link parameter definitions if necessary (see phenix.refine documentation). Also note that phenix.elbow is available to create restraint definitions for unknown ligands. Couldn't figure out what went wrong. Can somebody help me? Thanks. Jianghai +++++++++++++++++++++++++++++++ Jianghai Zhu, Ph.D CBR Institute for Biomedical Research Department of Pathology Harvard Medical School 200 Longwood Ave., Boston, MA 02115 Ph: 617-278-3211 Fx: 618-278-3232 +++++++++++++++++++++++++++++++