Comparison of classical trajectory and quantal close-coupling calculation of generalized cross sections for N_2~+-He mixtures

摘要

Quantal close-coupling calculations of the energy-dependent cross sections governing relaxation phenomena in depolarized Rayleigh scattering and nuclear magnetic resonance, and the Senftleben-Beenakker effect on viscosity, diffusion, and thermal conductivity have been performed for the system N_2~+-He. The corresponding classical expressions for these cross sections have been evaluated by the classical trajectory method and compared with the quantal results in the energy range 50 cm~(-1) to 838.6 cm~(-1). Excellent agreement is found for all 16 cross sections at the highest energy studied. While the agreement deteriorates for Most of the cross sections at lower energies, the quantization errors for the field-free viscosity and diffusion cross sections, which have non-vanishing spherical limits, are within 3 % for all energies considered.