Note that units are in Ångstroms and degrees. Also see the summary in the next section of this Appendix.
$opt CONSTRAINT stre atom1 atom2 value ... bend atom1 atom2 atom3 value ... outp atom1 atom2 atom3 atom4 value ... tors atom1 atom2 atom3 atom4 value ... linc atom1 atom2 atom3 atom4 value ... linp atom1 atom2 atom3 atom4 value ... ENDCONSTRAINT FIXED atom coordinate_reference ... ENDFIXED DUMMY idum type list_length defining_list ... ENDDUMMY CONNECT atom list_length list ... ENDCONNECT $end