We apply the well known Rayleigh–Ritz method (RRM) to the projection of a Hamiltonian operator chosen recently for the extension of the Rayleigh–Ritz variational principle to ensemble states. By means ...

Abstract: A method has been developed to improve the use of the RayIeigh-Ritz procedure. A criterion is established, which is a measure of the cumulative improvement due to the addition of more and ...