Eur. Phys. J. D (2021) 75: 62
https://doi.org/10.1140/epjd/s10053-021-00051-5

Regular Article - Atomic and Molecular Collisions

Coriolis coupling and isotopic effects on the quantum dynamics of H(${}^2$S) + NaH(X${}^1{\mathrm{\Sigma }}^{+}$) reaction

Department of Chemistry, School of Physical Chemical and Applied Sciences, Pondicherry University, 605 014, Puducherry, India

^c rpn.che@pondiuni.edu.in

Received: 11 November 2020
Accepted: 12 January 2021
Published online: 15 February 2021

Abstract

We here report the effect of Coriolis coupling (CC) on the dynamics of H(${}^2$S) + NaH(X${}^1{\mathrm{\Sigma }}^{+}$) reaction in the ground electronic state (1 ${}^2{A}^{\prime }$), employing a time-dependent wavepacket approach on a new potential energy surface. Initial state-selected and energy-resolved reaction probabilities, integral cross sections and thermal rate constants are obtained by performing the exact CC and centrifugal sudden (CS) calculations. The reactivity of hydride destruction channel (R1) is generally found to be greater than the hydrogen exchange channel (R2), in which the former channel is highly exoergic (by 2.788 eV) and the latter one is thermoneutral. The magnitude of reaction probabilities of R1 channel and the resonance features seen in that are effectively reduced at given energies by the exact CC approach compared to the CS model; on the other hand, CC enhances the reactivity of R2 channel compared to CS results. A comparison of CC and CS results reveals that neglecting the Coriolis coupling overestimates both cross sections and rate constants of R1 channel and underestimates the same for R2 channel. The CC also plays a significant role in the title reaction when the reagent NaH(v, j) molecule gets excited. In addition, the effect of isotopic substitution (H atom by D) on the H + NaH reaction is also examined and noted that the D + NaH reaction is highly reactive than the other isotopologues.