CLASSICAL PATH CALCULATIONS OF THE VIBRATIONAL-RELAXATION OF O-2(+) IN COLLISIONS WITH HE AT NEAR THERMAL ENERGIES

The vibrational relaxation rate constants for the recent measurements in the Innsbruck laboratory of the vibrational transitions 1 --> 0 and 2 --> 1 in the O-2(+)-He collision system mere calculated using the s emiclassical (classical path) method developed by Billing [G.D. Billin g, J. Chem. Phys., 61 (1974) 3340; Chem. Phys., 9 (1975) 359; Computer Phys. Rept., 1 (1984) 237]. The global 3D potential energy surface fo r dynamic calculations was constructed, using plausible additional ass umptions, on the basis of the procedure proposed by Gislason and Fergu son [E.A. Gislason and E.E. Ferguson, J. Chem. Phys., 87 (1987) 6474] to estimate the local (equilibrium geometry) properties of the O-2(+)- M and NO+-M collision complexes. The good agreement between theoretica l and experimental data, achieved in the collision energy range from t hermal energies up to approximate to 0.35 eV, provides strong support to the postulates of the method of Gislason and Ferguson. The possibil ities to further refine our procedure for construction of global 3D in teraction potentials and to extend ii to other classes of collision sy stems are also discussed.