Hello, I am running phenix version 1.9-1692. I have restrains for a nitric oxide ligand that I have used previously to refine a heme iron-NO linked structure. I have pasted them below. For some reason. The NO always gets moved a little to far from the iron. Here is a coot screen shot: https://www.dropbox.com/s/85c1ad2kecwebij/coot.png?dl=0 Can someone please help me resolve this issue? Thank you. -Yarrow ---------------------------------------------------------------------------------- metal edits file: refinement.geometry_restraints.edits { bond { action = *add atom_selection_1 = name FE and chain A and resname FE and resseq 499 atom_selection_2 = name N and chain A and resname NMO and resseq 510 distance_ideal = 1.75 sigma = 0.1 } } refinement.geometry_restraints.edits { angle { action = *add atom_selection_1 = name FE and chain A and resname FE and resseq 499 atom_selection_2 = name N and chain A and resname NMO and resseq 510 atom_selection_3 = name O and chain A and resname NMO and resseq 510 angle_ideal = 160 sigma = 5 } } refinement.geometry_restraints.edits { bond { action = *add atom_selection_1 = name FE and chain B and resname FE and resseq 499 atom_selection_2 = name N and chain B and resname NMO and resseq 510 distance_ideal = 1.75 sigma = 0.1 } } refinement.geometry_restraints.edits { angle { action = *add atom_selection_1 = name FE and chain B and resname FE and resseq 499 atom_selection_2 = name N and chain B and resname NMO and resseq 510 atom_selection_3 = name O and chain B and resname NMO and resseq 510 angle_ideal = 160 sigma = 5 } } --------------------------------------------------------------------- CIF file # data_comp_list loop_ _chem_comp.id _chem_comp.three_letter_code _chem_comp.name _chem_comp.group _chem_comp.number_atoms_all _chem_comp.number_atoms_nh _chem_comp.desc_level NMO NMO "nitric oxide " ligand 2 2 . # data_comp_NMO # loop_ _chem_comp_atom.comp_id _chem_comp_atom.atom_id _chem_comp_atom.type_symbol _chem_comp_atom.type_energy _chem_comp_atom.partial_charge _chem_comp_atom.x _chem_comp_atom.y _chem_comp_atom.z NMO N N N . -0.1324 -0.0924 0.5896 NMO O O O . 0.1324 0.0924 -0.5896 # loop_ _chem_comp_bond.comp_id _chem_comp_bond.atom_id_1 _chem_comp_bond.atom_id_2 _chem_comp_bond.type _chem_comp_bond.value_dist _chem_comp_bond.value_dist_esd NMO N O double 1.223 0.020 # loop_ _chem_comp_plane_atom.comp_id _chem_comp_plane_atom.plane_id _chem_comp_plane_atom.atom_id _chem_comp_plane_atom.dist_esd NMO plan-1 N 0.020 NMO plan-1 O 0.020