A Full Variational Calculation Based on a Tensor ProductDecomposition

Senese, Frederick A. and Beattie, Christopher A. and Schug, John C. and Viers, Jimmy W. and Watson, Layne T. (1989) A Full Variational Calculation Based on a Tensor ProductDecomposition. Technical Report TR-89-36, Computer Science, Virginia Polytechnic Institute and State University.

Abstract

A new direct full variational approach exploits a tensor (Kronecker) product decomposition of the Hamiltonian. Explicit assembly and storage of the Hamiltonian matrix is avoided by using the Kronecker product structure to form matrix-vector products directly from the molecular integrals. Computation-intensive integral transformations and formula tapes are unnecessary. The wavefunction is expanded in terms of spin-free primitive kets rather than Staler determinants of configuration state functions, and the expansion is equivalent to a full configuration interaction expansion. The approach suggests compact storage schemes and algorithms which are naturally suited to parallel and pipelined machines.