QUANTUM AND CLASSICAL CALCULATIONS OF TRANSPORT AND RELAXATION CROSS-SECTIONS IN HE-CO MIXTURES

Rigorous quantum and classical calculations for transport and relaxation properties of the gaseous mixture of He with CO have been carried out over a broad range of temperatures. The interaction potential employed was the one recently suggested from molecular beam experiments (W. Dilling, Ph.D. thesis, University of Gottingen, Germany, 1985) and the calculations were carried out with the correct dynamical couplings between tensorial basis sets in the quantum case, leading to the usual close-coupled (CC) equations. Classical trajectory (CT) calculations were also carried out and compared with the CC results. A combined use of CC and CT results, together with an appropriate choice of partition functions, is found to produce rather good agreement with the experimental findings for diffusion and mixture viscosity coefficients. The present results suggest ways for further testing the original potential energy surface and for extending the multiproperty analysis of it started earlier on with the scattering data of Dilling and the pressure broadening data of Green, Boissoles, and Boulet [J. Quant. Spectrosc. Radiat. Transfer 39, 33 (1988)].