MacroModel Reference Manual - ISP

Appendix C: Atom and Bond TypesTable C.1. Bond order values and symbols.Value Symbol Description0 . Zero order bond1 - Single bond2 = Double bond3 % Triple bond4 * Bond of undefined order (excluding zero order)C.3 MacroModel Atom TypesThe following table lists the atom types that are used in MacroModel and their equivalencies toatom types for other force fields. These atom types are defined in the atom.typ file. SeeSection C.1 on page 181 for a description of the atom.typ file and how to add atom types.Note that in MacroModel, 00 atoms are stored as type 0 in the atom connection table, and thatall current force fields require explicit hydrogens on heteroatoms.Table C.2. Atom types and equivalents.EquivalenciesNo. Symbol DescriptionMM2/MM3 Charmm Amber1 C1 Carbon - sp2 C2 Carbon - sp 2 2,3 CT,C C, C*, CA,CB, CC, CM,CF, CG, CN3 C3 Carbon - sp 3 1 CT CT4 CA United atom CH - sp 3 CH1E CH5 CB United atom CH 2 - sp 3 CH2E C26 CC United atom CH 3 - sp 3 CH3E C37 CD United atom CH - sp 2 CR1E CD, CE, CJ,CP8 CE United atom CH 2 - sp 29 CF United atom CH - sp10 CM Carbanion (C – )182MacroModel 9.7 Reference Manual