Preprints
https://doi.org/10.5194/egusphere-2023-1019
https://doi.org/10.5194/egusphere-2023-1019
22 May 2023
 | 22 May 2023

Reaction dynamics of P(4S) + O2(X 3Σ-) → O(3P) + PO(X 2Π) on a global CHIPR potential energy surface of PO2(X 2A1): implication for atmospheric modelling

Guangan Chen, Zhi Qin, Ximing Li, and Linhua Liu

Abstract. Reaction dynamics of P(4S) + O2(X 3Σ-) → O(3P) + PO(X 2Π) is thought to be important in atmospheric and interstellar chemistry. Based on the state-of-the-art ab initio energy points, we analytically constructed a global potential energy surface (PES) for the ground state PO2(X 2A1) using the combined-hyperbolic-inverse-power-representation (CHIPR) method. A total of 6471 energy points are computed by the multireference configuration interaction method with the Davidson correction and aug-cc-pV5Z basis set. The analytical CHIPR PES reproduces ab initio energies accurately with a root-mean-square deviation of 91.5 cm-1 (or 0.262 kcal/mol). The strongly-bound valence region of the PES has complicated topographical features with multiple potential wells and barriers. The attributes of the important intermediates are carefully validated with our geometry optimization results and previous computational results. Finally, the reaction probability, integral cross sections and rate constants for P(4S) + O2(X 3Σ-) → O(3P) + PO(X 2Π) are calculated using the quasi-classical trajectory and time-dependent wave packet methods. The trends of probability and integral cross section versus the collision energy can be divided into three stages, which are governed by the entrance barriers or exothermicity of the reaction. The rate constant demonstrates strong Arrhenius linear behavior at relatively low temperatures, but it deviates from this pattern at high temperatures. The calculated cross sections and rate constants are helpful for modelling the P chemistry in atmosphere and interstellar media.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Share

Journal article(s) based on this preprint

26 Sep 2023
Reaction dynamics of P(4S) + O2(X3Σg)  →  O(3P) + PO(X2Π) on a global CHIPR potential energy surface of PO2(X2A1): implications for atmospheric modelling
Guangan Chen, Zhi Qin, Ximing Li, and Linhua Liu
Atmos. Chem. Phys., 23, 10643–10659, https://doi.org/10.5194/acp-23-10643-2023,https://doi.org/10.5194/acp-23-10643-2023, 2023
Short summary
Download

The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

Short summary
We provide an accurate potential energy surface of PO2(X 2A1), which can be used for the...
Share