Effect of reagent rotation on isotopic branching in (He, HD⁺) collisions

Abstract

A three-dimensional time-dependent quantum mechanical wave packet approach is used to calculate reaction probability (P^R) and integral reaction cross section (σ^R) values for both the channels of the reaction He+HD⁺ (v=1; j=0, 1, 2, 3)→HeH(D)⁺+D(H), over a range of translational energy (E_trans) on the McLaughlin-Thompson-Joseph-Sathyamurthy (MTJS) potential energy surface using centrifugal sudden approximation for nonzero total angular momentum (J) values. The reaction probability plots as a function of translational energy for different J values exhibit several oscillations, which are characteristic of the system. It is shown that HeH⁺ is preferred over HeD⁺ for large J values and that HeD⁺ is preferred over HeH⁺ for small J values for all the rotational (j) states studied. The integral reaction cross section for both the channels and therefore the isotopic branching ratio for the reaction depend strongly on j in contrast to the marginal dependence shown by earlier QCT calculations. The computed results are in overall agreement with the available experimental results.