Time-dependent quantum wave packet studies of the F+HCl and F+DCl reactions

Abstract

Full three-dimensional time-dependent quantum wave-pack calculations have been carried out for the F+HCl and F+DCl reactions on a many-body expansion of the ground 2A′HClF potential energy surface. The calculated energy-dependence of reaction probability exhibits oscillating structure in the F+HCl reaction but not in the F+DCl system. The effects of initial state excitation on the total reaction probabilities as a function of collision energy are investigated for reactions from various initial vibrational and rotational states of HCl and DCl. Our results show that reagent vibrational and/or rotational excitation can generally lead to an increase in reaction probability at low collision energy and a slight decrease at relatively high collision energy. Thermal rate constants for the title reactions are calculated and they are in generally good agreement with experimental measurement. Investigation of steric effects for the reactions indicates that the H (or D) side of HCl (or DCl) molecule is only slightly favored for reactive attack and reaction proceeds from almost all attack angles. The present results indicate that the H/D kinetic isotope effect should not be totally neglected.

Stereo‐dynamics of the F + HCl → HF + Cl reaction

“…Sayos et al recently carried out an ab initio calculation at 311G(3d2f,3p2d) level using PUMP2/ PUMP4 method at 3400 geometries [12]. Based on the Sayos's PES, classical trajectory simulations [13] and quantum time-dependent wave packet dynamics calculations have been performed [14]. Enhancement of the reaction probability from reagent rotational excitation has been observed on Sayos's PES.…”

Accurate quantum wave packet calculations for the F + HCl → Cl + HF reaction on the ground 12A′ potential energy surface

“…3,7,9 It has been demonstrated for this kind of systems that it is more efficient to use product Jacobi coordinates in wave packet calculations. 13 The present state-to-state reaction probabilities are calculated using a wave packet method, with the MADWAVE3 code recently developed by Zanchet et al 14 The MADWAVE3 code has been well documented in the literature 14,15 and only the details relevant to the present work will be given here.…”

“…The title reaction has been the subject of many theoretical [1][2][3][4][5][6][7][8][9] and experimental [10][11][12] studies. Experimentalists, have focused on the determination of thermal rate constants.…”

Influence of collision energy and reagent rotation on the cross sections and product polarizations of the reaction F+ HCl

“…This value was then empirically reduced to 1.1 kcal/mol to obtain the experimental rate. QCT 12 as well as QM 13 calculations performed on this surface have been reported to analyze the reaction dynamics for both the title reaction and its deuterium isotope variant. Recently, a new benchmark ab initio PES(hereafter referred to as DHSN) for the 1 2 A state of FHCl has been constructed by Deskevich et al 14 Using this DHSN potential energy surface, the same group performed detailed quasiclassical trajectory(QCT) and quantum mechanical studies 15 of the title reaction, having found that the reagent rotation have a dramatic effect on the reaction probability.…”