title: Vibrational energy transfer in N2-N2 collisions: a new semiclassical study.
abstract: The vibrational energy relaxation in collisions between N2 molecules in the low- and medium-lying vibrationally excited levels was revisited using the semiclassical coupled-state method and the use of two different potential-energy surfaces having the same short-range potential recently determined from ab initio calculations but with different long-range interactions. Compared to the data reported in the classical work by Billing and Fisher [Chem. Phys. 43, 395 (1979)], the newly calculated vibration-to-translation rate constant K(1,0 / 0,0) is in much better agreement with the available experimental data over a large temperature interval, from T = 200 K up to T = 6000 K. Nevertheless, as far as the vibration-to-translation exchanges are concerned, the lower-temperature regime remains quite critical in that the new rate constants do not completely account for the rate constant curvature suggested by the experiments for temperatures lower than T = 500 K. The dependence of the state-selected vibration-to-vibration rate constants, K(v,v-delta v / 0,1), both upon the vibrational quantum number v and the gas temperature are calculated. The substantial deviations from previously found behaviors could have major consequences for the vibrational kinetic modeling of N2-containing gas mixtures.
authors.affiliation: Consiglio Nazionale delle Ricerche-Instituto di Metodologie Inorganiche e dei Plasma, c/o Dipartimento di Chimica, Università di Bari, via Orabona N.4, 70126 Bari, Italy. mario.cacciatore@ba.imip.cnr.it
authors.forename: M
authors.initials: M
authors.lastname: Cacciatore
authors.forename: A
authors.initials: A
authors.lastname: Kurnosov
authors.forename: A
authors.initials: A
authors.lastname: Napartovich