Quantum and quasi-classical dynamics of the C(3P) + O2(3Σ-g) → CO(1Σ+) + O(1D) reaction on its electronic ground state

Sugata Goswami; Juan Carlos San Vicente Veliz; Meenu Upadhyay; Raymond J Bemish; Markus Meuwly

doi:10.1039/d2cp02840a

Quantum and quasi-classical dynamics of the C(³P) + O₂(³Σ-g) → CO(¹Σ⁺) + O(¹D) reaction on its electronic ground state

Phys Chem Chem Phys. 2022 Oct 5;24(38):23309-23322. doi: 10.1039/d2cp02840a.

Authors

Sugata Goswami¹, Juan Carlos San Vicente Veliz¹, Meenu Upadhyay¹, Raymond J Bemish², Markus Meuwly^{1

3}

Affiliations

¹ Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland. m.meuwly@unibas.ch.
² Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117, USA.
³ Department of Chemistry, Brown University, RI, USA.

Abstract

The dynamics of the C(³P) + O₂(³Σ-g) → CO(¹Σ⁺) + O(¹D) reaction on its electronic ground state is investigated by using time-dependent wave packet propagation (TDWP) and quasi-classical trajectory (QCT) simulations. For the moderate collision energies considered (E_c = 0.001 to 0.4 eV, corresponding to a range from 10 K to 4600 K) the total reaction probabilities from the two different treatments of the nuclear dynamics agree very favourably. The undulations present in P(E) from the quantum mechanical treatment can be related to stabilization of the intermediate CO₂ complex with lifetimes on the 0.05 ps time scale. This is also confirmed from direct analysis of the TDWP simulations and QCT trajectories. Product diatom vibrational and rotational level resolved state-to-state reaction probabilities from TDWP and QCT simulations agree well except for the highest product vibrational states (v' ≥ 15) and for the lowest product rotational states (j' ≤ 10). Opening of the product vibrational level CO(v' = 17) requires ∼0.2 eV from QCT and TDWP simulations with O₂(j = 0) and decreases to 0.04 eV if all initial rotational states are included in the QCT analysis, compared with E_c > 0.04 eV obtained from experiments. It is thus concluded that QCT simulations are suitable for investigating and realistically describe the C(³P) + O₂(³Σ-g) → CO(¹Σ⁺) + O(¹D) reaction down to low collision energies when compared with results from a quantum mechanical treatment using TDWPs.