Convergence and Efficiency of the Valence Bond Self-Consistent Field Method

by Vanlenthe, J. H.; Verbeek, J.; Pulay, P.

A previously described method to optimize the non-orthogonal orbitals in a general valence bond wavefunction using the generalized Brillouin theorem is explored. The valence bond self consistent field (VBSCF) method has gained in efficiency by introducing the Direct Inversion in the Iterative Subspace (DIIS) method to cut the number of iterations and by reducing the number of matrix-elements calculated to minimize the time spent per iteration. Calculations on OH, Cr2 and F2 show considerable improvement in efficiency and illustrate the size and complexity of wavefunction that the method can handle.

Journal
Molecular Physics
Volume
73
Issue
5
Year
1991
Start Page
1159-1170
URL
https://dx.doi.org/10.1080/00268979100101841
ISBN/ISSN
1362-3028; 0026-8976
DOI
10.1080/00268979100101841