Wave packet and statistical quantum calculations for the He + NeH+ → HeH+ + Ne reaction on the ground electronic state

Abstract

A real wave packet based time-dependent method and a statistical quantum method have been used to study the He + NeH(+) (v, j) reaction with the reactant in various ro-vibrational states, on a recently calculated ab initio ground state potential energy surface. Both the wave packet and statistical quantum calculations were carried out within the centrifugal sudden approximation as well as using the exact Hamiltonian. Quantum reaction probabilities exhibit dense oscillatory pattern for smaller total angular momentum values, which is a signature of resonances in a complex forming mechanism for the title reaction. Significant differences, found between exact and approximate quantum reaction cross sections, highlight the importance of inclusion of Coriolis coupling in the calculations. Statistical results are in fairly good agreement with the exact quantum results, for ground ro-vibrational states of the reactant. Vibrational excitation greatly enhances the reaction cross sections, whereas rotational excitation has relatively small effect on the reaction. The nature of the reaction cross section curves is dependent on the initial vibrational state of the reactant and is typical of a late barrier type potential energy profile.

The interstellar formation and spectra of the noble gas, proton-bound HeHHe+, HeHNe+ and HeHAr+ complexes

“…However, a complete and reliable set of rovibrational spectroscopic data have yet to be produced for this simple system while other insights into its nature have been explored theoretically (Baccarelli, Gianturco & Schneider 1997;Panda & Sathyamurthy 2003;Bartl et al 2013). Other data for related noble gas molecules have been produced including those with helium (Fridgen & Parnis 1998;Lundell, Pettersson & Rasanen 1999;Koner, Vats & Panda 2012;Koner et al 2014;Borocci, Giordani & Grandinetti 2015;Grabowski et al 2016;Koner et al 2016), but full spectral charactization is still lacking for most of these structures.…”

State-to-State Dynamics of the Ne + HeH+ (v = 0, j = 0) → NeH+(v′, j′) + He Reaction

“…The RWP method followed here is discussed in detail in our previous article 37 and only a brief outline is presented here. The Hamiltonian operator for the Ne+HeH + system is expressed in reactant Jacobi coordinates as 39…”

“…Theoretical details of the method can be found in those original papers and on our previous study on the reverse reaction He+NeH + . 37 In essence, the initial-state-selected reaction probability for a specific value of the total angular momentum J is expressed as follows:…”

“…Both CS and CC approaches described in Ref. 37 have been also employed in the present study of the Ne+HeH + reaction. The values of the capture radius R min defining the onset of the intermediate region where the collision complex is assumed to form are 4.0 bohr for the reactant arrangement (Ne+HeH + ) and 4.4 bohr for the products (He+NeH + ).…”

“…Necessity of inclusion of Coriolis coupling (CC) to study bimolecular complex forming reactions has been discussed in the literature. 14,28,[32][33][34][35][36][37] In our recent article, 37 we reported the results of reactive scattering studies for the above reaction for different rovibrational reactant states via RWP and statistical quantum mechanical (SQM) methods, within CS approximation as well as including Coriolis coupled states.…”