Charge asymmetry in HD+

Abstract

Expanding the wave functions of the ground and excited states of HD1 ~or pde) in terms of spherically symmetric explicitly correlated Gaussian functions with preexponential multipliers consisting of powers of the internuclear distance, and using the variational method, we performed very accurate nonadiabatic calculations of all bound states of this system corresponding to the zero total angular momentum quantum number ~vibrational states; v50 – 22). The total and the transition energies obtained agree with the best available calculations. For each state we computed the expectation values of the d-p, d-e, and p-e interparticle distances. This is the first time these quantities were computed for HD1 using rigorous nonadiabatic wave functions. While up to the v520 state some asymmetry is showing in the d-e and p-e distances, for v521 and v522 we observe a complete breakdown of the Born–Oppenheimer approximation and localization of the electron almost entirely at the deuteron.