Effects of the rotational excitation of D2 and of the potential energy surface on the H++D2→HD+D+ reaction

Abstract

The H + +D 2 → HD+ D + reaction has been theoretically investigated by means of an exact quantum mechanical approach, a quasiclassical trajectory method, and two statistical methods based in the propagation of either wave functions or trajectories. The study addresses the possible changes on the overall dynamics of the title reaction when the D 2 diatom is rotationally excited to its v =0, j =1 state. In addition, the reactivity for the ground rotational state on two different potential energy surfaces ͑PESs͒, namely, the surface by Aguado et al. ͓J. Chem. Phys. 112, 1240 ͑2000͔͒ and the PES by Kamisaka et al. ͓J. Chem. Phys. 116, 654 ͑2002͔͒, is examined. Reaction probabilities and cross sections at 0.524 and 0.1 eV collision energies are calculated. The major differences with respect to the reaction initiated with D 2 in its ground rovibrational state are observed for the lowest collision energy E c = 0.1 eV. Differential cross sections have been found to depend to some extend on the PES employed. In addition, at E c = 0.1 eV further discrepancies in the total and rotational cross sections are noticeable.

Dynamics of the D+ + H2 → HD + H+ reaction at the low energy regime by means of a statistical quantum method

“…12 Analogously, as already discussed in the Introduction, differences in some dynamical attributes for the H + +D 2 → HD+D + reaction were found when two different potentials were employed in the calculations at higher collision energies. 14 The observed resonances observed here and for the scattering reactions for the H + 3 system 4 can be directly related with H + −H 2 radiative association processes. 44,60 In recent experimental radio frequency ion trap investigations, the deviations from the expected statistical behaviour were tentatively attributed to the rather low number of states accessible to the H + 3 complex at the temperature regime (11 K-33 K) considered there.…”

“…These two approaches have been applied in common for a better understanding of the dynamics of several atomdiatom reactions such as N+H 2 , 53 O+OH, 54 H + +H 2 , 4,55,56 and H + +D 2 . 14,31 Numerical details of the TIQM calculation performed by Honvault and Scribano were given before. 49 The number of rovibrational states for the reactant and product channels and of helicity components was found to guarantee converged results down to energies within the 10 −4 eV-10 −3 eV range.…”

“…In particular, PESs from Refs. 9 and 10 were comparatively tested 14 for the H + +D 2 →HD+D + reaction. Reaction probabilities, rovibrational distributions, and differential cross sections (DCSs) at collision energies of E c = 0.1 eV and 0.524 eV obtained for each surface revealed differences which seem to be more noticeable as the energy decreases.…”

Beyond universality: Parametrizing ultracold complex-mediated reactions using statistical assumptions

“…Since the PES is characterized by a deep well or complex (≈4.5 eV), as illustrated in Fig. 1, rigorous statistical models [23,24] have been applied to this reaction and isotopic variants in the low and thermal energy regimes [20,[24][25][26][27] in good agreement with accurate …”

Cold and ultracold dynamics of the barrierless D+ + H2 reaction: Quantum reactive calculations for ∼R−4 long range interaction potentials

“…In parallel to the electronic structure developments, a selection of theoretical methods of varying accuracy has been applied to the study of the H + + H 2 reaction dynamics. [62][63][64][65][66][67][68][69][70][71][72][73][74][75][76] Of all the possible isotopic variants of the H + + H 2 reaction that of the deuteron with H 2 is exothermic due to the different zero-point energies (ZPEs) of reactants and products and hence is appropriate for its study at the cold and ultra-cold energy regimes. 77 The isotopic substitution makes possible to readily identify reactants and products by mass spectrometry or spectroscopic techniques.…”