I am trying to link my sugar molecule (FUC-GAL-NGA-FUC), Lewis y, for phenix.refine, but I keep on getting an error message. I am a beginner at this so I just don't know how to make the links. For , example, I am using this: refinement.pdb_interpretation { apply_cif_link { data_link = BETA1-2 residue_selection_1 = chain C and resname GAL and resid 224 residue_selection_2 = chain C and resname FUC and resid 223 } apply_cif_link { data_link = BETA1-3 residue_selection_1 = chain C and resname GAL and resid 224 residue_selection_2 = chain C and resname NGA and resid 225 } apply_cif_link { data_link = BETA1-3 residue_selection_1 = chain C and resname NGA and resid 225 residue_selection_2 = chain C and resname FUC and resid 226 Number of atoms: 46 Number of conformers: 1 Conformer: "" Number of residues, atoms: 4, 46 Unusual residues: {'GAL%DEL-HO2%DEL-HO3': 1, 'NGA%DEL-O1%DEL-HO3': 1, 'FUC%DEL-O1': 2} Unexpected atoms: {'NGA%DEL-O1%DEL-HO3,O1L': 1, 'NGA%DEL-O1%DEL-HO3,O': 1} Classifications: {'undetermined': 4} Modifications used: {'DEL-HO2': 1, 'DEL-HO3': 2, 'DEL-O1': 3} Link IDs: {None: 3} Unresolved non-hydrogen bonds: 3 Unresolved non-hydrogen angles: 6 Unresolved non-hydrogen dihedrals: 4 Unresolved non-hydrogen chiralities: 2 Unresolved apply_cif_link angles: 1 Unresolved apply_cif_link chiralities: 1 Number of atoms with unknown nonbonded energy type symbols: 2 "HETATM 5649 O NGA C 225 .*. O " "HETATM 5655 O1L NGA C 225 .*. O " Time building chain proxies: 2.31, per 1000 atoms: 0.41 Sorry: Fatal problems interpreting PDB file: Number of atoms with unknown nonbonded energy type symbols: 2 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. Any help and direction would be appreciated. Grant