On the Hellmann-Feynman theorem and the corrections to the energy in the Rayleigh-Schrodinger perturbation theory

In this work we present an alternative method, based on the Hellmann-Feynma n theorem, to generate energy corrections within the standard Rayleigh-Schr odinger perturbation theory. As a result, compact expressions for the corre ctions to the energy at different orders are obtained. We also review a met hod that allows us to calculate the corrections to the wave function needed in the energy calculations. Finally, our results are compared with those o btained by other authors by a different technique.