Rotational and Vibrational Energy Transfer in Diatomic and Polyatomic Molecules

Abstract

Exact quantum mechanical calculations on vibrational/rotational transitions in molecules are only possible or numerically feasible for at few — mainly — hydrogen containing (low mass) systems. It has, however, turned out that semiclassical (classical path) methods are sufficiently accurate to provide quantitative results for both light and heavy molecules. For the latter the semi-classical approach is furthermore about the only possibility for obtaining vib/rot cross sections. We have developed a hierarchy of methods which are able to give accurate cross sections and rate coefficients for diatomic and small polyatomic molecules and qualitative information on larger polyatomic systems.