The role of intersystem crossing in the reactive collision of S+(4S) with H2.

We report a study on the reactive collision of S+(4S) with H2, HD, and D2 combining guided ion beam experiments and quantum-mechanical calculations. It is found that the reactive cross sections reflect the existence of two different mechanisms, one being spin-forbidden. Using different models, we demonstrate that the spin-forbidden pathway follows a complex mechanism involving three electronic states instead of two as previously thought.

The long-lived reactive nitrogen species in the troposphere: DFTB model for atmospheric applications.

The longest lived reactive NO molecule formation in a dry and clean air environment under a high-temperature shock wave was investigated under three basic reactions (R2 for the O + NO system, R6 for the NO + NO system, and R7 for the NO + O system) in the atmospheric environment. With certain approaches, a DFTB3 model was used, which gave results close to the density functional theory. In the calculations, the related reactions up to 250 ps were examined at individual specific temperatures, and the temperature ranges that contributed to the formation of the NO molecule were determined.

Oxygen Molecule Formation and the Puzzle of Nitrogen Dioxide and Nitrogen Oxide during Lightning Flash.

Unlike the compounds of the natural air atmosphere, the lightning systems are primarily focused on NO(XΠ), NO(1A'), and O(P) concentrations that occurred newly and highly in the ground electronic structure. While the NO/NO concentrations ratio is about 2000 during the lightning flash, this ratio becomes about 0.8 right after the lightning flash.