Invariance properties of the moments of the hamiltonian matrix as a test of the correctness of configuration interaction programs
Abstract
An invariance of the spectrum of a full configuration interaction (CI) matrix with respect to unitary transformations of the orbital basis set is frequently used as a test of the correctness of CI programs. In this paper we argue that using instead the invariance properties of the first two moments of the spectrum of the matrix is both simpler and more conclusive. Explicit formulae for the moments are derived and their usefulness is illustrated by several examples.
 Publication:

Computer Physics Communications
 Pub Date:
 October 1987
 DOI:
 10.1016/00104655(87)900683
 Bibcode:
 1987CoPhC..47...83D