Hi, All, I have a structure calculated with NMR restraints but it has quite some geometry violation, such as torsion angles, clashes etc. The structure has a small molecule ligand bound. Is it possible to add an CIF file for the ligand and use phenix.geometry_minimization to idealize/optimize the protein structure? I have tried the following and phenix reported an error for missing CIF file. phenix.geometry_minimization model.pdb pdb_intepretation.apply_cif_restraints.restraints_file_name=ligand.cif what would be the correct syntax to add ligand cif for this geometry_minimization? Or what would be the proper way to idealize/optimize a protein structure with ligands present? The structure optimization during NMR calculation is not good enough in my case. Thanks! Charles *************************************************** Charles Chen Research Instructor University of Pittsburgh School of Medicine Department of Anesthesiology ******************************************************