Nonadiabatic dipole polarizabilities ofH2+andD2+ground states

The recently reported discrepancy between the experimentally determined value for the dipole polarizabity of the ${\mathrm{H}}_2^{+}$ ground state [Phys. Rev. A 56, R4361 (1997); 57, 4065 (1998)] and the adiabatic value calculated in the clamped nucleus approximation [Mol. Phys. 65, 679 (1988)] has motivated a fully nonadiabatic treatment of the problem. Finite element analysis is used to obtain a direct solution of the zeroth- and first-order equations of perturbation theory. The nonadiabatic value for ${\alpha }_s$ is consistent with the experimental measurement.