The resonance energies for the hydrogen atom in an electric field, both the real and imaginary parts, have been calculated together from the real Rayleigh-Schrödinger perturbation series by Borel summation. Padé approximants were used to evaluate the Borel transform. The numerical results compare well with values obtained by the complex-coordinate variational method and by sequential use of Padé approximants.

• Received 29 October 1984

DOI:https://doi.org/10.1103/PhysRevA.32.1338