Complex angular momentum theory of molecular collisions - new phase rules for rotationally inelastic diffraction scattering in atom-homonuclear diatomic molecule collisions

Authors: McCabe, P., Connor, J.N.L, Thylwe, K.-E.
Document Type: Article
Pubstate: Published
Journal: J. Chem. Phys.
Volume: 98   2947-2961
Year: 1993


New phase rules have been derived for the rotationally inelastic diffraction scattering of an atom with a homonuclear diatomic molecule. The phase rules are obtained by applying semiclassical complex angular momentum techniques to the infinite order sudden approximation. The new phase rules are of three types, which are denoted weak coupling, intermediate coupling, and strong coupling. Higher-order terms have been derived for each type of phase rule. A systematic computational study of the accuracy of the phase rules has been carried out for a deformed inverse power potential energy of the form in (r( gamma )/r)/sup n/, n>or=3, where r( gamma )=r/sub 0/+r/sub 2/P/sub 2/(cos gamma ). Additional calculations are reported for the Ne-D/sub 2/ and He-N/sub 2/ collision systems, using more realistic interaction potential energies.