THIS INFORMATION IS OBSOLETE AND IS PROVIDED ONLY FOR ITS HISTORICAL VALUE

by Michael Ramek, Institut für Physikalische und Theoretische Chemie, Technische Universität Graz, A- 8010 Graz, Austria

This subroutine generates initial density matrices for molecular ab-initio SCF calculations with standard basis sets (STO-3G, STO-3G*, 4-31G**, 6-311G, and 6- 311G**) for H to Ar. The density matrix guess is constructed as a factorized matrix consisting of precomputed blocks of atomic density matrices along the main diagonal. Sample calculations show that this guess, compared with usual guesses (core-guess, HO(u,¼)ckel-guess), reduced the number of SCF cycles up to 40%. All modifications necessary for adding this subroutine to GAUSSIAN 80 and HONDO 76 are given in the appendices.

FORTRAN 77 Lines of Code: 3144