|
606. AMSOL: An SCF Program Incorporating Free Energies in
Aqueous Solution and Semiempirical Charge Models
(Version 4.5)
*
by Christopher J. Cramer,(a) Gregory D. Hawkins,(a) Gillian C. Lynch,(a) David J. Giesen,(a) Donald G. Truhlar,(a) and Daniel A. Liotard(b) (a)Department of Chemistry, University of Minnesota, Minneapolis, MN 55455 (b)Laboratoire de Physicochemie Theorique, Universite de Bordeaux, France (based on AMPAC+version 2.1 by D. A. Liotard, E. F. Healy, J. M. Ruiz, and M. J. S. Dewar and including options from GEPOL by E. Silla, I. Tunon, and J. L. Pascual-Ahuir) AMSOL+version 4.5 is a semiempirical SCF package for calculating (i) polarized wave functions, solute energies, and free energies of solvation of neutral and charged solutes in aqueous solution and (ii) wave functions, energies, and class IV atomic charges for neutral and charged molecules in the gas phase. AMSOL carries out SCF calculations in the NDDO approximation. Free energy of solvation terms may be added to the Fock operator to account for aqueous solvation effects. There are two kinds of solvation terms: CDS terms proportional to the solvent-accessible surface area and ENP generalized Born polarization terms based on a distributed monopole representation of the solute charges with dielectric screening. Both CDS and ENP terms require the calculation of solvent-accessible surface areas, and three options are provided: DOTS, GEPOL, and ASA. Five parameter sets are available for solvation calculations in version 4.5: AM1-SM1 is the original general parameter set for general ions or neutrals. AM1-SM1a is a more specialized parameter set applicable to neutral molecules without hypervalent centers, three-center bonds, or unusual hybridization at N or O. AM1-SM2 is an improved solvation model with a general parameter set. It is especially better for hydrophobic effects. Am1-SM2.1 is similar to AM1-SM2, but it allows use of the efficient and more flexible radial quadrature schemes. PM3-SM3 is like AM1-SM2 except that, unlike the earlier versions, the PM3 parameter set is used in the solute Hamiltonian instead of the AM1 parameter set. Parameters are available for H, C, N, O, F, P, S, Cl, Br, and I in all solvation models. AMSOL may also be used for AM1 and PM3 calculations without solvent. In these calculations the CM1A and CM1P charge models may be used to calculate class IV atomic charges, if desired. The solvation and charge models are described further in the following references: AM1-SM1 and AM1-SM1a: "General Parameterized SCF Model for Free Energies of Solvation in Aqueous Solution," C. J. Cramer and D. G. Truhlar, Journal of the American Chemical Society 113, 8305-8311, 9901(E) (1991). AM1-SM2: "An SCF Solvation Model for the Hydrophobic Effect and Absolute Free Energies of Aqueous Solvation," C. J. Cramer and D. G. Truhlar, Science 256, 213-217 (1992). PM3-SM3: "PM3-SM3: A General Parameterization for Including Aqueous Solvation Effects in the PM3 Molecular Orbital Model," C. J. Cramer and D. G. Truhlar, Journal of Computational Chemistry 13, 1089+1097 (1992). overview: "AM1-SM2 and PM3-SM3 Parameterized SCF Solvation Models for Free Energies in Aqueous Solution," C. J. Cramer and D. G. Truhlar, Journal of Computer-Aided Molecular Design 6, 629+666 (1992). ASA algorithm and other computational improvements introduced in versions 4.0 and 4.1: "Improved Methods for Semiempirical Solvation Models," D. A. Liotard, G. D. Hawkins, G. C. Lynch, C. J. Cramer, and D. G. Truhlar, Journal of Computational Chemistry, in press. Preprints are available from Research Reports Coordinator, Supercomputer Institute, 1200 Washington Avenue South, Minneapolis, MN 55415; request UMSI preprint number 94/143. CM1A and CM1P: "Class IV Charge Models: A New Semiempirical Approach in Quantum Chemistry," J. W. Storer, D. J. Giesen, C. J. Cramer, and D. G. Truhlar, to be published in Journal of Computational Chemistry. Preprints are available from Research Reports Coordinator, address above; request UMSI preprint number 94/144. AMSOL+version 4.5 is written in FORTRAN 77 with the INCLUDE extension. It has been tested on Cray-2, Cray X-MP-EA, and Cray Y-MP C90 computers with the UNICOS 7.C.3 and 7.0.5 versions of Unix and the cft77 compiler, on a DEC 3000/500X AXP workstation with the OSF Unix operating system version 1.3 and the f77 compiler, on an IBM RS/6000 workstation with the AIX Unix operating system version 3.2.3 and the xlf compiler, on a Sun SPARCStation SLC with the SunOS operating system 4.1.2 and the f77 compiler, and on an IRIS 4D workstation with the IRIX Unix operating system version V.3. AMSOL+version 4.5 is distributed as a set of 137 files, including C shell scripts for compiling and linking, for interactive job submission, and for submitting batch jobs under the NQS queuing system. The distribution also includes a brief on-line manual (ASCII documentation file), and a Postscript version of an AMPAC+version 2.1 documentation file, a 4x-run test suite, and a set of subroutines with Cray library calls which may be used to make a partially optimized Cray version, called version 4.5c. AMSOL+versions 4.5 and 4.5c are copyrighted but not licensed. Usage of the code implies acceptance of a user agreement not to redistribute it except to co-workers. FORTRAN 77 with INCLUDE extension; portable Unix version (AMSOL+version 4.5) and Cray version (AMSOL+version 4.5c) Lines of FORTRAN code: 34,107 Total length of distribution files, including FORTRAN code, optional C timing utility, Unix scripts, test suite, and documentation files: 66,570 lines |