Rotational energy transfer in H2+H2

Abstract

Quantum-mechanical close-coupling calculations for state-to-state cross sections and thermal rates are reported for H2+H2 collisions. Two recently developed potential energy surfaces (PES) for the H2−H2 system are applied, namely, the global potential surface from the work of A.I. Boothroyd, P.G. Martin, W.J. Keogh, M.J. Peterson, J. Chem. Phys., 116 (2002) 666, and a restricted, model surface from the works of P. Diep, J.K. Johnson, J. Chem. Phys., 113 (2000) 3480; ibid. 112, 4465. The low temperature limit is investigated. We found significant differences in cross sections and corresponding thermal rates calculated with these two PESs.

A comparative study of the low energy HD+o-/p-H2 rotational excitation/de-excitation collisions and elastic scattering

“…12, 13 and in. 34 Therefore in this paper a new attempt has been undertaken to carry out alternative computational methods for HD+H 2 collision. In case of the BMKP and DJ PESs the necessary steps for each potential have been described in Secs.…”

“…These PESs have been used in several different calculations. [32][33][34][35][36] However, in our previous works 12,34 we found that in the case of low energy H 2 +H 2 collision these PESs provide different results for some specific state-resolved cross sections. The difference may be up to an order of magnitude.…”

“…It would be useful to check how well the computed thermal rates (8) in this work satisfy the detailed balance equation (34). Fig.…”

“…This fact was also confirmed in work. 13 The BMKP PES, probably, needs future improvements, 12,13,34 because the DJ PES gives better agreement with existing experiments for H 2 +H 2 than the BMKP potential.…”

Ultracold collisions between two light indistinguishable diatomic molecules: Elastic and rotational energy transfer in HD+HD

“…[39] it was shown that for a specific excitation rotational transition in the H 2 + H 2 inelastic scattering, for example, in H 2 (0) + H 2 (0) → H 2 (0) + H 2 (2), the BMKP PES provides an incorrect cross section when compared to the DJ potential. The comparison was also carried out with available experimental data [40].…”