Quasiclassical trajectory calculations and quantal wave packet calculations for vibrational energy transfer at energies above the dissociation threshold

Quantal wave packet calculations and quasiclassical trajectory calculations are reported for vibrational energy transfer and dissociation in collinear atom-diatom collisions. The system considered has the masses of H+H₂ and is modelled with an extended LEPS potential energy surface. The conditions considered are initial vibrational states n₁ = 0, 1, and 4 and initial relative translational energies up to 12 eV for the wave packet calculations and up to 13 eV for the trajectory calculations. This is higher in energy than previous comparisons of quantal and trajectory calculations. The quantal transition probabilities show higher thresholds than the trajectory ones, and then they oscillate about the trajectory results. The first and second moments of the final vibrational action are similar for both kinds of calculation.