Energy approximants and perturbation theory for screened Coulomb potentials

Abstract

By applying the Hellmann–Feynman theorem and the virial theorem to screened Coulomb potentials, the energy is shown to be expressible in terms of an integral. Making use of the Padé approximant for the integrand, the modified [3,4] energy approximant obtained speeds up to the convergence of the energy perturbation series. The prediction of the modified [3,4] energy approximant for an electron in the Yukawa potential is in good agreement with that of numerical integration.