Understanding the effect of vibrational excitation in reaction dynamics: the Ne + H2+(v = 0–17, j = 1) → NeH+ + H, Ne + H+ + H proton transfer and dissociation cross sections

Abstract

The dependence of the cross section (σ) of the Ne + H₂⁺ → NeH⁺ + H proton transfer reaction on the vibrational excitation of H₂⁺, v = 0–17 and j = 1, was analyzed in detail at the collision energies (E_col) of 0.7 and 1.7 eV, using the quasi-classical trajectory (QCT) method and the PHHJ3 and LZHH potential energy surfaces (PESs), taking advantage of the rich experimental data available for this reaction as a function of H₂⁺(v). The efficiency of vibrational excitation to promote the reaction was investigated from the analysis of the σ(QCT) vs. v dependence in terms of the average reaction probability, maximum impact parameter, regions of the (late barrier) PES explored, and taking into account the Ne + H₂⁺ → Ne + H⁺ + H dissociative channel, which plays a dominant role at high enough total energies. Although the earlier PHHJ3 PES performs rather well, the LZHH PES QCT results show a better agreement with the experiment. On the other hand, some artifacts were found in recently reported QCT calculations (unphysical oscillations in σ(QCT) as a function of v), and the present study shows that special care is needed when carrying out QCT calculations involving highly excited vibrational states.