Dear all, The protein was covalently linked by my ligand and I used JLigand to generate the link record and the .cif file. This file can be used in Refmac successfully. But the .cif file cannot be recognized by phenix.model_vs_data nor phenix.refine. The program runs with the following message: Sorry: Fatal problems interpreting model file: Number of atoms with unknown nonbonded energy type symbols: 19 Please edit the model 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. Any suggestions how to do this would be greatly appreciated. Another question is, how can I generate a restraints file for COOT to do real space refinement? The .cif file is imported in COOT, but when I do real space refinement, the link bond still takes apart. Best wishes! Lu -- 卢作焜 南开大学新生物站A202 Lu Zuokun, Ph.D. Candidate College of Life Science, Nankai University