Time-Dependent Wave Packet Quantum and Quasi-Classical Trajectory Study of He + H₂⁺, D₂⁺→ HeH⁺+ H, HeD⁺+ D Reaction on an Accurate FCI Potential Energy Surface

Abstract

The quantum scattering dynamics and quasi-classical trajectory (QCT) calculations have been carried out for the title reaction on an accurate potential energy surface (PES) computed using the full configuration interaction (FCI). On the basis of the PES, the integral cross-sections of He + H 2 + (v = 0−3, j = 1) → HeH + + H reaction have been calculated, and the results are generally agreed with the experimental cross-sections obtained by Tang et al. [J. Chem. Phys. 2005, 122, 164301] after taking into account the experimental uncertainties, which proves the reliability of implementing dynamics calculations on the FCI PES. The reaction probability of He + D 2 + (v = 0−2, j = 0) → HeD + + D reactions for total angular momentum J = 0 and the integral cross-section (ICS) have been calculated. The significant quantum effect has been explored by the comparison between the QCT reaction probabilities (or ICS) and the quantum mechanical (QM) reaction probabilities (or ICS), which may be attributed to the deep well in the PES of this light atoms system. Furthermore, the role of Coriolis coupling (CC) effects has also been found not important by the comparison between the CC calculation and the centrifugal sudden (CS) approximation calculation, except that the CC total cross-sections for the v = 1 and 2 states show the collision energy-dependent behaviors in the low-energy area, which are different from those based on the CS calculation.

Dynamical properties of S(3P) + HD reaction on 13A″state and their quantum wavepacket calculation

“…To understand the different threshold energy for the two product channels, we calculated the VA barriers for products and , which are 0.95 and 1.05 eV (measured relative to the energy of the ground state of the reactants), respectively. The slight difference between the threshold energy and the VA barriers can be attributed to the tunneling effect, which has also been found in other atom transfer reactions at below threshold energies …”

“…The slight difference between the threshold energy and the VA barriers can be attributed to the tunneling effect, which has also been found in other Hatom transfer reactions at below threshold energies. [31][32][33] As shown hereinbefore, an exact CC calculation of J > 0 reaction probabilities would require us to couple all possible K states, and the maximum value of K is equal to J. Yet such calculations will be very time consuming.…”

The He + ${\rm H}_2^+$H2+ → HeH+ + H reaction: Ab initio studies of the potential energy surface, benchmark time-independent quantum dynamics in an extended energy range and comparison with experiments

“…II. Although several classical trajectories, 32 stereodynamical, 33 and approximated quantum dynamical studies 34,35 have already been performed with the PESs of Ref. 31, rigorous quantum dynamical calculations were still lacking, so it was not clear whether these PESs really improve the agreement with the experimental data.…”

Exploring the reaction dynamics of O(3P)+ (X2)→OH+(X3Σ−)+ H(2S) reaction with time‐dependent wave packet method

“…And for the same collision energy, the ICSs of different vibrational quantum number have little differences. As we know, the increasing of the reagent vibrational quantum number can increase the total energy of the reaction system, which can increase the ICS of He + , , S + HD . However, for the title reaction, the reaction has not been promoted with the reagent vibration energies increasing.…”

“…As we all know, some reactions, such as He + , N + , H/D + , S + HD/ are influenced by the reactants vibrational and rotational level changing. Sahoo et al explored reactive scattering problem of the D + + in various initial states, which used a coupled three‐dimensional time‐dependent wave packet formalism in hyperspherical coordinates.…”