THIS INFORMATION IS OBSOLETE AND IS PROVIDED ONLY FOR ITS HISTORICAL VALUE

aDepartment of Chemistry and Supercomputer Institute, University of Minnesota, Minneapolis, MN 55455-043l

bStewart Computational Chemistry, 15210 Paddington Circle, Colorado Springs, CO 80921-2512

cSan Diego Supercomputer Center, P.O. Box 85608, San Diego, CA 92186-9784

dEnvironmental Molecular Sciences Laboratory, Battelle Pacific Northwest Laboratories, Richland, WA 99352

eDepartment of Chemistry, Miami University, Oxford, OH 45056

MORATE (Molecular Orbital RATE calculations) is a computer program for direct dynamics calculations of unimolecular and bimolecular rate constants of gas- phase chemical reactions involving atoms, diatoms, or polyatomic species. The potential energies, gradients, and higher derivatives of the potential are calculated whenever needed by semiempirical molecular orbital theory without the intermediary of a global or semiglobal fit.The dynamical methods used are conventional or variational transition state theory and multidimensional semiclassical approximations for tunneling and nonclassical reflection. The computer program is a conveniently interfaced package consisting of the POLYRATE program, version 6.5, for dynamical rate calculations, and the MOPAC program, version 5.05mn, for semiempirical electronic structure computations. All semiempirical methods available in MOPAC, in particular MINDO/3, MNDO, AM1, and PM3, can be called on to calculate the potential and gradient. In addition, the program has flexible options for NDDO calculations with specific reaction parameters (NDDO- SRP calculations). First the program optimizes the geometries of the reactant(s), conventional transition state (if any exists), and product(s). Then the minimum energy path is calculated by one of several methods. Variational transition states are found by a one-dimensional search of generalized-transition-state dividing surfaces perpendicular to the minimum-energy path. The variational transition state of canonical variational theory (CVT), improved canonical variational theory (ICVT), and/or microcanonical variational theory (mVT) is found by interpolation of data stored on a grid. Tunneling probabilities are calculated analytically by the Wigner approximation, by numerical quadrature using semiclassical adiabatic methods for zero or small curvature of the reaction path, by numerical quadrature using the large-curvature (version 3) method, and/or by the microcanonical optimized multidimensional tunneling approximation. MORATE also calculates the equilibrium constant for the reaction, and it has an option to perform runs in which conventional transition state theory rate constants are calculated without calculating a reaction path.

MORATE also supports a dual-level mode in which calculations may be performed with semiempirical molecular orbital theory for the lower level and with data at any level of theory read in from an external file for the higher level. The higher-level data are interpolated to provide corrections to the lower level. The advantage of such dual-level calculations is that one needs a minimum number of higher-level calculations (which may, e.g., be extended-basis-set ab initio calculations with electron correlation, and hence expensive).

The code is distributed with five documentation files containing detailed revision histories, instructions for input, and other useful information for users. One is the MORATE manual, which does not repeat most of the material in the POLYRATE and MOPAC manuals; the second is the MOPAC+version 5.05mn manual, which does not repeat most of the material in the MOPAC+version 5.0 manual. The third and fourth documentation files are the POLYRATE+version 6.5 and MOPAC+version 5.0 manuals. The fifth file is an expanded version of the input chapter of the POLYRATE manual containing the expanded input options available in MORATE that are not in the POLYRATE manual.

An earlier version (4.5) of MORATE is described in T. N. Truong, D.-h. Lu, G. C. Lynch, Y.-P. Liu, V. S. Melissas, J. J. P. Stewart, R. Steckler, B. C. Garrett, A. D. Isaacson, A. Gonzalez-Lafont, S. N. Rai, G. C. Hancock, T. Joseph, and D. G. Truhlar, Comp. Phys. Comm., 143, 75 (1993).

MORATE+version 6.5 requires a license. Copies of the non-profit license may be obtained from QCPE, the principal investigator (Donald G. Truhlar), or Rozeanne Steckler and must be signed and returned to QCPE with the program order. There is no additional fee above the usual QCPE service charge for the license if the program is to be used for non-profit or academic research. Persons who want to obtain a commercial license should contact the principal investigator directly, as QCPE is currently handling only non-profit licenses.

Lines of Code: 313,066

ANSI-standard FORTRAN77 (except that subroutine names are in lower case) with the INCLUDE and DO WHILE extensions. Tested successfully on Cray C90 and Cray X- MP-EA under UNICOS 7.C.3, IBM RS/6000-550 under AIX 3.2.5, Silicon Graphics IRIS Indigo R4000 under IRIX System V.4 Release 5.2, and Sun SPARCStation IPX under SunOS 4.1.2.