Noble-gas quenching of rovibrationally excited H2

Collisions between noble-gas atoms and hydrogen molecules are investigated theoretically by solving the time-independent Schrödinger equation. Various initial states of the molecule are considered and the calculations are performed for each system over a large range of collision energies. Cross sections for quenching of rovibrationally excited states of H2 are reported for Ar and Kr colliders and comparisons are made with previous calculations involving He. For both Ar and Kr colliders, the effect of vibrational excitation is found to be more pronounced for ortho-H2. The T→0 limit of the total quenching rate coefficient, which is presented here as the imaginary part of a complex scattering length, is found to increase by about 7 orders of magnitude as the vibrational quantum number of ortho-H2 is increased from 1 to 10. Trends in the energy dependence for the heavier systems are very similar, including resonance behavior, which suggest that the dynamics of heavy noble-gas H2 systems are less sensitive to the fine details of the potential.