Dynamics and resonances of the H(²S) + CH⁺(X¹Σ⁺) reaction in the electronic ground state: a detailed quantum wavepacket study

Abstract

Initial state-selected and energy resolved channel-specific reaction probabilities, integral cross sections and thermal rate constants of the H(S) + CH(XΣ) reaction are calculated within the coupled states approximation by a time-dependent wave packet propagation method. The new ab initio global potential energy surface (PES) of the electronic ground state (1 A') of the system, recently reported by Li et al. [J. Chem. Phys., 2015, 142, 124302], is employed for this purpose. All partial wave contributions up to the total angular momentum J = 60 are considered to obtain the converged integral reaction cross section up to a collision energy of 1.0 eV. Thermal rate constants are calculated by averaging the reaction cross sections over the Boltzmann distribution of energies and compared with the available theoretical and experimental results for the temperature range 10-1000 K. Investigation of the channel-specific reaction attributes shows that the H abstraction (CH destruction) channel is highly favored over the H exchange channel. The effect of rotational and vibrational excitations of the CH reagent on the dynamics is also studied. The resonances formed during the course of the reaction are also identified by calculating the transition state spectrum and characterized in terms of the eigenfunctions and lifetimes. More than 260 vibrational levels are obtained and their eigenfunctions are calculated, which are represented in terms of the nodal assignments and the eigenenergies. They reveal both the local and hyperspherical behavior for the bound and quasibound states of the CH complex in the ground 1 A' surface. The lifetime analysis of the quasibound states indicates that the CH resonances survive for as long as ∼400 fs at high energies (E ∼ 2.0 eV) and are expected to decay faster with further increasing energy. Finally, the type of mechanism for the formation of the product (C + H) is elucidated.

Dynamical and Mechanical Insights into the Li(2S)+ HCl() Reaction: A Detailed Quantum Wavepacket Study

“…We here employed a time‐dependent wavepacket (WP) method, an effective approach to study the Li( 2 S )+HCl($${X^1 \Sigma ^ + }$$ ) reaction on the new HYLC PES [27] . Since this method has been successfully applied to many such elementary reactions [34–38] and is well documented in the literature, [39–41] we briefly outline them in this section.…”

Exact quantum dynamics study of the H(2S)+SiH+(X1Σ+) reaction on a new potential energy surface of SiH 2+(X2A1) *

“…[25,26] As so far, there are no experimental and other theoretical results of H + SiH + reaction compared with the results of this work, however, H + CH + reaction has been investigated extensively. [2,3,5,27,28] Furthermore, the topographical properties of CH + 2 (1 2 A ) are essentially same with SiH + 2 (X 2 A 1 ) system, [4,9] hence, the variation tendency and resonance structure of reaction probability, ICS and rate constant of H + SiH + reaction are compared with the ones of H + CH + reaction.…”

“…During the past decades, the construction of accurate global potential energy surface (PES) of the methylene ion CH + 2 and related dynamics investigation have aroused great interest because of their importance in atmospheric chemistry and astrophysics. [1][2][3][4][5][6] Comparatively speaking, the global PES of SiH + 2 system and related dynamical calculations are seldom reported. For the silicon semiconductor industry, SiH + and H are known to be two reactive intermediate species in chemical-vapor deposition process, and the investigation on H + SiH + reaction is of great practical significance.…”

Experimental study of the proton-transfer reaction C + H2+ → CH+ + H and its isotopic variant (D2+)

“…Numerous theoretical studies have been conducted on the dynamics of the C + ( 2 P) + H 2 ( 1 S + g ) -CH + ( 1 S + ) + H( 2 S) reaction [70][71][72] and the reverse process [73][74][75][76] involving the ground electronic state 1 2 A 0 of CH 2 + . However, we are unaware of any such theoretical investigations for the C( 3 P) + H 2 + ( 2 S + g ) reaction, which proceeds through excited states of CH 2 + .…”