SEMICLASSICAL AND QUANTAL CALCULATION OF STATE-TO-STATE GENERALIZED CROSS-SECTIONS FOR N-2(-HE MIXTURES())

A semi-classical calculation of state-to-state generalized cross-secti ons has been performed for the first time and compared with quantal cl ose-coupling calculations for the system N-2(+)-He. At the total colli sion energy of 838.6 cm(-1), the semi-classical results for the cross- sections diagonal in the tensorial ranks agree with the close-coupling results within 20%, while those for the non-diagonal cross-sections g ive at least semi-quantitative agreement. It is expected that the agre ement will improve when energy-averaged cross-sections are computed. A t high collision energies, where large rotational quantum numbers are involved, quantal calculations cease to be feasible, and the semi-clas sical method provides a practical and reasonably accurate procedure to compute state-to-state cross-sections.