The importance of O3 excited potential energy surfaces in O2–O high-temperature kinetics.

The mechanism of vibrational relaxation and dissociation in the O₂–O system at elevated temperatures is investigated by means of molecular dynamics. The most recent O₃ potential energy surfaces (PESs), obtained from the first principles quantum mechanical calculations [Varga et al., J. Chem. Phys. 147, 154312 (2017)], are used to derive a complete set of state-specific rate coefficients of vibrational energy transfer and dissociation. Unlike most of the previous efforts that utilize only the lowest and supposedly most reactive 1¹A′ O₃ PES [A. Varandas and A. Pais, Mol. Phys. 65, 843 (1988)], this paper demonstrates the necessity to account for a complete ensemble of all excited O₃ PESs that correlate with O₂(X) and O(³P) when high-temperature kinetics is of interest. At the same time, it is found that the Varandas 1¹A′ O₃ PES adequately describes vibrational energy transfer and dissociating dynamics when compared to the most recent 1¹A′ O₃ PES by Varga et al. [J. Chem Phys. 147, 154312 (2017)]. The differences between this new dataset and previous rate coefficients are quantified by the master equation model. [ABSTRACT FROM AUTHOR]