XmlmmCIF equivalent: chem_comp_plane Data items in the CHEM_COMP_PLANE category provide identifiers for the planes in a chemical component. The atoms in the plane are specified in the CHEM_COMP_PLANE_ATOM category. XmlmmCIF equivalent: chem_comp_plane/number_atoms_all The total number of atoms in the plane. XmlmmCIF equivalent: chem_comp_plane/number_atoms_nh The number of non-hydrogen atoms in the plane. XmlmmCIF equivalent: chem_comp_plane/comp_id This data item is a pointer to _chem_comp.id in the CHEM_COMP category. XmlmmCIF equivalent: chem_comp_plane/id The value of _chem_comp_plane.id must uniquely identify a record in the CHEM_COMP_PLANE list.