THIS INFORMATION IS OBSOLETE AND IS PROVIDED ONLY FOR ITS HISTORICAL VALUE

by Eugene I. Tolpin, Department of Chemistry, University of Louisville, Louisville, Kentucky 40208

The general program performs extended Hückel calculations on molecules containing atoms belonging to the first five rows of the periodic table. It is a translated and expanded version of QCPE 256, differing from it by allowing: 1) d orbitals to be represented by a double zeta function; and 2) bonding to be analzyed through bond indices and valencies according to Armstrong, Perkins, and Stewart, and through a Mulliken population analysis.

Extended Hückel calculation programs such as this one use a basis set composed only of valence-shell orbitals, in particular here, Slater-type orbitals (STOs). The maximum number of orbitals permissible is governed by the dimensions of various matrices. The current form of the program allows a maximum of 150 orbitals of all types. Additional restrictions include a maximum of 25 hydrogen atoms and 23 principle or main atoms. The large size of these matrices in turn causes the program to require a large amount of core (400 Kb) for execution.

This is a version of QCPE 358 especially adapted for use on CDC computers with the CDC EXTENDED FORTRAN compiler.

FORTRAN EXTENDED (CDC) Lines of Code: 2600 Recommended Citation: E. I. Tolpin, QCPE 11, 380 (1979).