SCIGRESS - Computational Tools - MOPAC
MOPAC is a general-purpose semiempirical molecular orbital package for the study of solid state and molecular structures and reactions. The semiempirical Hamiltonians MNDO, AM1, PM3, PM6, RM1, and MNDO-d are used in the electronic part of the calculation to obtain molecular orbitals, the heat of formation and its derivative with respect to molecular geometry. Using these results MOPAC calculates the vibrational spectra, thermodynamic quantities, isotopic substitution effects and force constants for molecules, radicals, ions, and polymers. For studying chemical reactions, a transition state location routine and two transition state optimizing routines are available. For users to get the most out of the program, they must understand how the program works, how to enter data, how to interpret the results, and what to do when things go wrong.
Please refer to www.openmopac.net for details on how to obtain the program.