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465. XASW: Atomic X-a and Molecular Multiple Scattering X-a
Electronic Structure Calculations (Version 2.0)
by Michael Cook, Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138 and David A. Case, Department of Chemistry, University of California, Davis, California 95616 This system sets up and solves the X-a scattering-wave equations. It is for the VAX 11/780 running under VMS 3.1. However, it can readily be converted to IBM hardware. The restriction on this system is that it uses an atomic radial mesh of 150 points. Other array dimensions in the code are written as ampersanded variables [e.g., ESTATE(&NST)] which can be edited to any desired value. Instructions and suggested array dimensions are given in the documentation. For a spin-restricted polarization-basis calculation on benzene, it takes 14 seconds to create the symmetry file, 29 seconds to create the starting potential, 2 minutes and 36 seconds to do an energy search, 14 minutes 18 seconds to converge to self-consistency, and 5 minutes 8 seconds to calculate the one-electron properties. (These times are all in VAX CPU.) The present package is fully double-precision and contains all the auxiliary programs needed to set up and converge a molecular system. The program contains a quasirelativistic option and an option for symmetry- optimized calculation of G-matrix elements. This package is version 2 of XASW. It supersedes version 1.In addition to the molecular self- consistent-field, X-a program (XASCF), the package includes four other programs: XATOM, a version of the Herman-Skillman atomic X-a program; XASYMFN, which creates symmetry-adapted basis-function coefficients; XAINPOT, which creates a starting potential; and XAONELP, a program for calculating one-electron properties. FORTRAN IV (VAX) Lines of Code: 12,000 NOTE: This system is sufficiently complex that it will be distributed on its own magnetic tape which will be highly blocked. The largest block will be 10640. |