Some aspects of energy transfer in molecular and atomic collisions

It is maintained that quenching of 0(1D) by collision with N2 and the ionization of Na by collision with vibrationally excited N2 proceed via the formation of a collision complex. Once the complex is formed, even a weak coupling between the two states involved, can induce a large transition probability because the crossing seam of the two potential energy surfaces is passed many times during the life of the complex. Qualitatively reasonable potential energy surfaces for 0(1D) + N2 are constructed and classical trajectory calculations carried out to show that the cross section for complex formation is indeed appreciable; a statistical model is used to determine the quenching probability of the complex; results are in good agreement with experiment. Ab initio (SCF) potential energy surface calculations are carried out for N2-Na, N2-Na+, and N-2-Na+ systems; the points are fit to simple standard functions; a statistical model is developed for the ionization of Na by vibrationally excited N2. The classical S-Matrix theory is applied to rotational excitation of CO by collision with He; the results are in qualitative agreement with quantum mechanical calculation