Study by crossed beams and ab initio techniques of an environmentally interesting process: Gas-phase high energy collisions between N2O(1Σ+) and Li+(1S0)

Abstract The environmentally relevant gas phase collisions between ground states N 2 O molecules and lithium ions have been studied by crossed-beams techniques and fluorescent emissions. Total emission cross-sections for Li( 2 P u ) and Li( 2 D g ) formation in the 0.100–5.00 keV laboratory energy range have been measured in absolute units. Different potential energy surfaces involved in the non-adiabatic electron transfer processes have been calculated at the ab initio complete active space interaction configuration (CASCI) level of theory in the collinear configuration system. These gave information on different excited states including those asymptotically correlating the prominent process leading to the formation of Li( 2 P u ) and N 2 O + . Also, a detailed full dimensional analysis of the systems’ ground PES has been made at the perturbation second order Moller–Plesset (MP2) level. From the ab initio calculations and using simple model analytical equations for excitation functions a qualitative interpretation of the measured data for the dominant non-adiabatic process is given.