Photoionization of Oriented HD(¹Σ⁺) Yields Vibrating HD⁺(²Σ⁺) with Charge Breathing and Small Charge Transfer

The eigenfunctions of the Hamiltonian associated with the oriented vibrating HD⁺(²Σ⁺) ion are calculated beyond the Born-Oppenheimer approximation in the nuclear frame. This makes it possible to study the fully correlated electron-nuclear dynamics of the HD⁺(²Σ⁺) after ionization of the HD(¹Σ⁺) molecule. The dynamics is then characterized by the time-dependent probability densities and flux densities of the individual particles, i.e., deuteron, proton, and electron. The flux densities confirm that, although the electric dipole moment changes over time, there is no charge migration, as might be expected from the separation of energy levels of the vibronic states. Instead, the variations of the electric dipole moment over time are caused by small charge transfer and asymmetric charge vibration. Fourier transforms of the time-dependent probability and flux densities uncover the net asymmetric effective potential acting on the electron.