MOPAC Manual. Sixth Edition. A General Molecular Orbital Package

Abstract : MOPAC is a general-purpose, semi-empirical molecular orbital program for the study of chemical reactions involving molecules, ions, and linear polymers. It implements the semi-empirical Hamiltonians MNDO, AM1, PM3, and MINDO/3 and combines the calculations of vibrational spectra, thermodynamic quantities, isotopic substitution effects, time-dependent effects, and force constants in a fully integrated program. Elements parametrized at the PM3 level are H, Be, C, N, O, F, Mg, Al, Si, P, S, Cl, Zn, lja, lje, As, Br, Cd, In, Sn, Sb, Te, I, Hg, Tl, Pb, and Bi. Within the electronic part of the calculation, molecular and localized orbitals excited states up to sextets, chemical bond indices, charges, etc. are computed. Both intrinsic and dynamic reaction coordinates can be calculated. A transition-state location routine and two transition-state optimizing routines are available for studying chemical reactions.