The PI will continue current NSF research completing theoretical quantum chemical calculations of rate coefficients and cross sections for the dissociative recombination of nitrogen. The measurements will help resolve a long standing discrepancy between measured ionospheric nitrogen concentrations and model predictions. Dissociative recombination rate constants and atomic quantum yields will be calculated as a function of ion vibrational level and electron temperature. Also, the PI will calculate the dissociative recombination of nitric oxide with an electron as an important parameter to many ionospheric models. Finally, the PI will continue studying the rate constants for collisional deexcitation of excited states of oxygen by ground state oxygen. Because these processes are important relaxation mechanisms for excited oxygen (especially at low altitudes), they have been identified by others as major sources of hot atomic oxygen in the thermosphere, and have never been measured in the laboratory or calculated theoretically.***
