Example: quenching of the radiating state of diatomic molecule due to collisional intramolecular ev transition

The quantitative understanding of the processes of quenching of electronic excitation and intramolecular and intermolecular EV energy transfer in collisions involving diatomic molecules is of importance for modeling practically important plasma chemical systems, such as gas lasers, gas-discharge lamps, and upper atmosphere.

It can be seen from the right figure that the approach based on Kintech Lab expertise provides the quantitative description of the complicated EV energy transfer process.

Intramolecular EV (electron-vibrational) energy transfer Na2(B1Пu,v) + Ar(1S) -> Na2((2)1Sigmag+,v') + Ar(1S) leading to quenching of the radiating B1Пu – state of Na2 is a characteristic example of such process. From the physical point of view, this process is due to the removal of the crossing between the B1Пu and (2)1Sigmag+ states of Na2 by the approaching Ar atom, see left figure. Splitting is due to short-range exchange interaction. The rate constants kПS(v,v’) were evaluated within the framework of an infinite-order sudden approximation based on the notion of vibronic diabatic atom-molecule potential curves and excluding the rotational degrees of freedom of Na2. The exchange interaction between Na2 and Xe was evaluated using the asymptotic method developed in the USSR and specially designed for medium and long distances between the interaction particles.