The O + NO( v) Vibrational Relaxation Processes Revisited

Reactive and Nonreactive Collisions between NO(X2Π) and O(3P) under Hyperthermal Conditions

Quasiclassical trajectory calculations are performed for hyperthermal collisions between NO(X²Π) and O(³P) on recently developed potential energy surfaces for the lowest doublet and quartet states of the NO₂ system. Three product channels are investigated, and their branching fractions are in reasonably good agreement with the recent crossed molecular beam study at 84 kcal/mol of collision energy. The dominant inelastic channel has a strong forward scattering bias and a high translational energy distribution with limited internal excitation in the scattered NO. The exchange channel has significantly higher NO internal excitation and is also forward biased. The abstraction channel producing internally excited O₂ has the smallest branching fraction and a broader angular distribution also with a forward peak. The angular and translational energy distributions in the three channels are consistent with experiment, but the agreement is not always quantitative. The sources of the differences are discussed. Finally, the impact of NO vibrational excitation on the reactive channels and the corresponding rate coefficients are reported.

The N(4S) + O2(X3Σ−g) ↔ O(3P) + NO(X2Π) reaction: thermal and vibrational relaxation rates for the 2A′, 4A′ and 2A′′ states

Cross sections, rates, equilibrium constants and vibrational relaxation times for the N(⁴S) + O₂(X³Σ−g) ↔ O(³P) + NO(X²Π) reaction from simulations on new, RKHS-based surfaces for the three lowest electronic states.

Thermal activation of methane by MgO+: temperature dependent kinetics, reactive molecular dynamics simulations and statistical modeling

The kinetics methane activation (MgO⁺ + CH₄) was studied experimentally and computationally by running and analyzing reactive atomistic simulations.

Calculation of Vibrational Relaxation Times Using a Kinetic Theory Approach

In the present work, a method for computation of vibrational relaxation times based on a kinetic theory definition is utilized to calculate vibrational relaxation times of molecules present in air (N₂, O₂, and NO) in collisions with air species particles. An overview of available experiment VT relaxation time measurements, as well as quasi-classical trajectory (QCT) calculation results, and various empirical models, is given. Different inelastic cross-section models are used for the computation of the relaxation times, and their parameters are adjusted to fit the available experimental data and QCT results. It is shown that the proposed method of calculation can give a quantitative and qualitative agreement with the available data in a wide range of temperatures; the obtained interaction parameters may be used not only for vibrational relaxation time calculation within a multitemperature framework but also for development of state-specific models for use in CFD and DSMC codes.