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581. MOPAC: Version 5.0 of MOPAC for the IBM 3090
by James J. P. Stewart, The Frank J. Seiler Research Lab, U. S. Air Force Academy, Colorado Springs, Colorado 80840 Converted by Dennis Gerson, IBM E/S National Support Center, Dallas, Texas 75234 This version of MOPAC incorporates all the previously available Hamiltonians, namely, MINDO/3, MNDO and AM1. In addition there is also incorporated the MNDO-PM3 Hamiltonian. PM3 has the same theoretical form as MNDO and AM1, the main difference being that in PM3 the parameters for 12 elements are optimized simultaneously. This results in a lowering of the average errors in heats of formation without loss of accuracy in geometries, dipoles or I.P.s. Elements available within each method in Version 5.0 are:
MINDO/3 H B C N O F MNDO H Li Be B C N O F Al Si P S Cl Cr Zn Ge Br Sn I Hg Pb AM1 H B C N O F S Cl Br I PM3 H C N O F Al Si P S Cl Br I In addition, point charges simulating Na and K ions are available. The failure to achieve an SCF is still annoying, but a recent article by Mitin on a modified level-shift technique suggested how to dynamically damp electron- density oscillations. A modification of this is present in Version 5.0; the overall effect is to increase the probability of obtaining an SCF. A hyperpolarizability calculation has been written by Henry Kurtz of Memphis State University which allows polarizability and first and second hyperpolarizabilities of molecules and ions (but not polymers) to be calculated. The energy partition option has been rewritten by Prof. Tsuneo Hirano. In its new form it is easy to use and is useful for giving insights into intermolecular and intramolecular interactions. The data file is unchanged, but the output has been modified to include several changes recommended by users. This means that MOPAC Version 5.0 output may not be compatible with other software which reads MOPAC output. Several minor bugs are fixed in Version 5.0; and a few minor enhancements (mainly dealing with error messages) have been made. All changes are documented in the MOPAC Version 5.0 manual. This is a fully certified version of MOPAC 5.0. FORTRAN 77 (IBM VM) Lines of Code: 30,000 |