Anti-alignment driven dynamics in the excited states of molecules under strong fields

We develop two novel models of the H-2(+) molecule and its isotopes from which we assess quantum-mechanically and semi-classically whether the molecule anti-aligns with the field in the first excited electronic state. The results from both models allow us to predict anti-alignment dynamics even for the HD+ isotope, which possesses a permanent dipole moment. The molecule dissociates at angles perpendicular to the field polarization in both the excited and the ground electronic state, as the population is exchanged through a conical intersection. The quantum mechanical dispersion of the initial state is sufficient to cause full dissociation. We conclude that the stabilization of these molecules in the excited state through bond-hardening under a strong field is highly unlikely.

Automated summary

Two novel models developed for H-2(+) molecule and its isotopes demonstrate the anti-alignment with the field in the first excited electronic state, even for the HD+ isotope with a permanent dipole moment. The dissociation of the molecule at angles perpendicular to the field polarization occurs in both the excited and the ground electronic state, as a result of population exchange through a conical intersection. The quantum mechanical dispersion of the initial state is sufficient to cause full dissociation, leading to the conclusion that bond-hardening stabilization in the excited state under a strong field is highly unlikely.