Comment on the rotational excitation in hydrogen-halie-rare-gas collisions

Computational and experimental results for rotational excitation in atom-hydrogen-halide collision are just becoming available. Such processes are particularly important in many chemical lasers, and there is an obvious need for reliable estimates of the cross sections. One possible approach is to employ an information-theoretic synthesis. Previous applications of the information-theoretic approach to rotational energy transfer were largely confined to homonuclear diatomics. The recent accurate close-coupling computations of Collins and Lane for low-energy He-HF collisions provide a basis for a detailed comparison. We show that the magnitudes of the relative cross sections and their energy dependence, as computed by Collins and Lane, can be reproduced by the information-theoretic synthesis. We then proceed to predict similar results for HCl-rare-gas collisions.