This award supports continued theoretical quantum chemical studies of the dissociative recombination of N2 and the collisional quenching of O+(2D) by O(3P). The studies of N2 will provide rates and quantum yields of atomic products as a function of ion vibrational level and electron temperature. These quantities, which are difficult if not impossible to measure in the laboratory, will allow for detailed ionospheric modeling of N2 and its dissociative recombination products. The results will help to resolve the long standing discrepancy between measured ionospheric N2 concentrations and the model results. The complex interaction between the N2 dissociation channels will be handled with a coupled equations approach. Also, a new dissociative route of recombination mechanism involving the mixing of dissociation routes of the same symmetry through the electron-ion states will be treated. These techniques will also be applied to a study of the dissociative recombination of NO+ in order to determine the total rate and the atomic quantum yields from v=O. The N(2D) quantum yield from dissociative recombination of NO+ is an important quantity in many ionospheric models. The rates for the aeronomic collisional quenching reactions of O+(2D) and O+(2P) by O(3P) have never been calculated theoretically or determined in the laboratory. Potential curve calculations will be completed for the quenching of O+(2D) and the cross section and rate will be calculated by solving the coupled equations. A similar approach will be used for the quenching of O+(2P).
