Rotational excitation of diatomic molecules by atoms

Abstract

The strong coupling correspondence principle is applied to the rotational excitation of diatomic molecules by atoms. The problem is formulated for arbitrary spherically symmetric atoms and molecules in Sigma states. Various limiting cases are examined and, where possible, compared with other calculations. In particular the excitation of N₂ by Ne is considered and comparisons with close coupling calculations are made. It is shown that for wide ranges of quantum numbers and incident energies the methods used are accurate to within 10% and are faster by about two orders of magnitude. For greater initial excitation of the molecule the methods described should become more accurate.