Dynamics Study of the N(⁴S) + O₂ Reaction and Its Reverse

Abstract

We report quasiclassical trajectory calculations for the reaction N(4 S) + O 2 f NO + O by focusing on the rovibrational distributions of the NO product molecule at a collisional energy of 3 eV and the temperature dependence of the rate constant. The calculations employ the lowest adiabatic sheet of a recently reported (Varandas, A. J. C. J. Chem. Phys. 2003, 119, 2596) multisheeted double many-body expansion potential energy surface for the 2 A′ states of NO 2 , improved via a multiple energy-switching scheme to attain nearspectroscopic accuracy in the vicinity of the deep X 2 A 1 minimum. For the quartet state, the calculations employ single-sheeted potentials from various sources, except for the rate constant where the results are taken from the literature. The rate constant for the reverse endothermic reaction is calculated by dividing the rate constant for the forward reaction by the equilibrium constant calculated using statistical mechanics. For both reactions, the agreement with the recommended rate constants is good. The vibrational distributions of NO are found to agree with previously reported theoretical estimates, which show fair agreement with the general trends observed from experiment.

N2, O2, NO state-to-state vibrational kinetics in hypersonic boundary layers: The problem of rescaling rate coefficients to uniform vibrational ladders

“…They, respectively, are This last equation is the same reported in Ref. [40]. Details on the calculation of both the equations are reported in the Appendix A.…”

A Theoretical Study of Rate Coefficients for the O + NO Vibrational Relaxation

“…Such three-body correction terms, which have been included by dressing the input diatomic curves, have been calibrated using both theoretical and experimental data. After diagonalization, a manifold of eight 2 A′ potential energy surfaces is obtained, with the lowest adiabatic state having been morphed with an effective spectroscopic polynomial form 25 26 The number of reported studies for the 1 2 A′′ electronic state is much smaller than that for the ground state. Gillespie et al 27 reported bending curves for the equilibrium NO distance of the NO 2 molecule, which have been used by Duff and Sharma 20 to construct a global potential energy surface.…”

Quantum mechanical investigations of the N(S4)+O2(XΣg−3)→NO(XΠ2)+O(P3) reaction

“…Reaction ͑1͒ has been the subject of a large number of experimental [17][18][19][20][21][22][23][24][25][26] and theoretical [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] investigations. The experimental studies have focused on two aspects: first, to evaluate thermal rate coefficients over a wide range of temperatures from 300 to 5000 K, 19,24,25 and second, to determine the rovibrational level populations of the NO͑͒ products.…”