One-electron wavefunctions: variational perturbation theory

The ground-state wavefunction of H2+ is calculated using variational perturbation theory. The accuracy of the wavefunction is demonstrated by comparing calculated energies and expectation values with the corresponding exact values. Extrapolation of the ratios of the perturbation energies and of the expectation value coefficients is used to study the asymptotic behavior of the perturbation expansions.