Angular momentum coupling schemes in the quantum mechanical treatment of <i>P</i>-state atom collisions

Abstract

For the multichannel Schrödinger equations which arise in the quantum mechanical close coupling treatment of atomic collisions involving fine structure effects, alternative representations are developed by angular momentum algebra. The various representations are closely related to Hund’s coupling schemes for rotating diatomic molecules. Matrix elements for the electrostatic interaction and for the orthogonal transformations which connect the various representations, are given explicitly for the case when only one atom has internal angular momenta and follows LS coupling. The limit of large angular momenta, of interest under semiclassical conditions, is also considered. Some examples of applications to P atom collisions are discussed.