New insights for mesospheric OH: multi-quantum vibrational relaxation as a driver for non-local thermodynamic equilibrium.

The question of whether mesospheric OH() rotational population distributions are in equilibrium with the local kinetic temperature has been debated over several decades. Despite several indications for the existence of non-equilibrium effects, the general consensus has been that emissions originating from low rotational levels are thermalized. Sky spectra simultaneously observing several vibrational levels demonstrated reproducible trends in the extracted OH() rotational temperatures as a function of vibrational excitation.

Collision dynamics of O(3P) + DMMP using a specific reaction parameters potential form.

Starting from previous benchmark CBS-QB3 electronic structure calculations (Conforti, P. F.; Braunstein, M.

Energetics and dynamics of the reactions of O(3P) with dimethyl methylphosphonate and sarin.

Electronic structure and molecular dynamics calculations were performed on the reaction systems O((3)P) + sarin and O((3)P) + dimethyl methylphosphonate (DMMP), a sarin simulant. Transition state geometries, energies, and heats of reaction for the major reaction pathways were determined at several levels of theory, including AM1, B3LYP/6-311+G(d,p), and CBS-QB3. The major reaction pathways for both systems are similar and include H-atom abstraction, H-atom elimination, and methyl elimination, in rough order from low to high energy.

Hyperthermal atomic oxygen source for near-space simulation experiments.

A hyperthermal atomic oxygen (AO) beam facility has been developed to investigate the collisions of high-velocity AO atoms with vapor-phase counterflow. Application of 4.5 kW, 2.

Ab initio energies and product branching ratios for the O+C3H6 reaction.

Intermediate and transition-state energies have been calculated for the O+C3H6 (propene) reaction using the compound ab initio CBS-QB3 and G3 methods in combination with density functional theory. The lowest-lying triplet and singlet potential energy surfaces of the O-C3H6 system were investigated. RRKM statistical theory was used to predict product branching fractions over the 300-3000 K temperature and 0.