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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
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