Ground-state eigenvectors for many configuration wavefunctions

Abstract

An n-th order steep descent technique for determining the lowest eigenvector of the matrix equation, [ H − E S] c = 0, is investigated. The convergence is suited to the molecular wavefunction configuration interaction problem, in particular where bases are used which may be nearly overcomplete in certain regions of the vector space. The algorithm is also suited to computer solutions for large matrices, since it can be broken down to apply to blocks of convenient dimensions which may be treated iteratively and separately.