On the origin of the dynamical differences between the Tang and Dalgarno-Henry-Roberts potentials for rigid rotor H₂-H collisions

We compare our quasiclassical trajectory results for the J=0 →2 rotational excitation in rigid rotor H₂-H collisions with the close-coupling results of Choi and Tang on two different potentials. We trace the dynamical differences between the two potentials to the differences in the ellipticity of the repulsive potential-energy contours. We also discuss the application of our results to rotational excitation on the most accurate Siegbahn-Liu-Truhlar-Horowitz surface for the collision.