Hi everyone, I need to input a parameter file describing the bond lengths of a metal chelator complex in my protein. I used a text file containing the commands with .params extension. when I add this file in GUI inputs in refinement, it gives a message "Phenix did not recognize the file type". What is the file type I should use? The file contained commands similar to the following with my metal and ligand atom names. refinement.geometry_restraints.edits { zn_selection = chain X and resname ZN and resid 200 and name ZN his117_selection = chain X and resname HIS and resid 117 and name NE2 asp130_selection = chain X and resname ASP and resid 130 and name OD1 bond { action = *add atom_selection_1 = $zn_selection atom_selection_2 = $his117_selection symmetry_operation = None distance_ideal = 2.1 sigma = 0.02 slack = None } bond { action = *add atom_selection_1 = $zn_selection atom_selection_2 = $asp130_selection symmetry_operation = None distance_ideal = 2.1 sigma = 0.02 slack = None } } Then I used command line to run "phenix.refine model.pdb data.mtz elbow.cif restraints_edits.params" it again gave error saying .params is an unknown file type. Am I doing anything wrong and is there any other way to fix the distances of the metal chelator complex. Thanks Subhani