Tunneling of a diatomic molecule with many bound states

We study the effects of multiple bound states on the probability of tunneling of a homonuclear diatomic molecule incident upon a potential barrier in one dimension. We obtain additional bound states by several means: by varying individual features of the binding potential as well as increasing the mass of the two atoms. We find that the tunneling behavior of a molecule with a large number of bound states (similar to 30) is drastically different from that for a molecule with a small number of states (less than or similar to 5). Further, we find that the effect of multiple bound states on the proabability of tunneling is largely dependent upon the separation between the bound-state energies. It is also found that intermediary transitions between many bound states results in significantly larger reductions in the probability of tunneling. Finally, we investigate molecules of different masses and observe common qualitative features. We focus on molecules incident upon a delta barrier but we also consider Gaussian barriers.