The reduced partitioning procedure revisited

Abstract

The present article reports on the inherent connections between perturbation and variation theories known as the Reduced Partitioning Procedure. The topic formed the basis for the PhD thesis of Rodney J. Bartlett. In this work he analysed the interrelations between current (at the time) perturbation and variational theories, with particular reference to the Lanczos algorithm, the Krylov vectors, Hankel determinants as well as inferences from the Padé–Stieltjes moment problem and associated Lippman–Schwinger-type principles. Numerical computations for small molecular systems displayed rapid convergence, in excellent agreement with the deduced optimal properties of the method.