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236. GAUSSIAN 70: Ab Initio SCF-MO Calculations on
Organic Molecules
by W. J. Hehre, Department of Chemistry, University of
California, Irvine, California 92664; W. A. Lathan,
Department of Chemistry, University of Rochester,
Rochester, New York 14627; R. Ditchfield, Department of
Chemistry, Dartmouth College, Hanover, New Hampshire
03755; M. D. Newton, Department of Chemistry,
Brookhaven National Laboratory, Upton, L.I., New York
11973; and J. A. Pople, Department of Chemistry,
Carnegie Mellon University, Pittsburgh, Pennsylvania
15213
GAUSSIAN 70 is a system of FORTRAN programs written for
the IBM 360/370 and overlayed so as to require a
maximum of 266 Kb of storage.
Two series of bases are built into the program: the
minimal STO-NG1 and the extended 4-31G2 sets. In
addition, provision has been made for the input of
arbitrary sets of (s and p) functions subject to the
overall size restrictions:
Maximum number of atoms - 35
Maximum number of atomic orbitals - 75
Maximum number of Gaussian functions per atomic
orbital - 6
Maximum total number of Gaussians - 240 (s and p
functions only).
The system has been designed with flexibility and ease
of use in mind, as well as overall program efficiency;
and it enables the user to perform such tasks as
geometry and basis set optimization and potential
surface scanning with little more input than is
normally required for a single calculation.
Input and operating details are extensively documented
in COMMENT cards within the program. In addition,
three sample inputs and associated outputs are provided
for initial testing.
Primarily because of the novel design of the integral
evaluation package, ab initio calculations on moderate-
sized molecules (up to 10 or 12 heavy atoms) with the
minimal STO-3G basis are only about 20 times more
costly than with currently available semiempirical
schemes (CNDO, INDO, MINDO). Thus, for those who now
use QCPE 141 and related programs and who are not
working on exceptionally large molecules, this system
may well be worth the effort to examine thoroughly.
_________
References:
1. W. J. Hehre, R. F. Stewart and J. A. Pople, J.
Chem. Phys., 51, 2657 (1969); W. J. Hehre, R.
Ditchfield, R. F. Stewart, and J. A. Pople, ibid., 52,
2191 (1970).
2. R. Ditchfield, W. J. Hehre and J. A. Pople, ibid.,
54, 724 (1971); W. J. Hehre and W. A. Lathan, ibid.,
56, 5255 (1972).
FORTRAN IV (IBM 360/370)
Lines of Code: 13,370
Recommended Citation: W. J. Hehre, J. A. Pople et al.,
QCPE 11, 236 (1973).
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