On an approximation in scattering theory

Abstract

An approximation, based on regional trial functions, is used to calculate excitation cross sections between some optically connected states of hydrogen and of the alkalis, lithium, sodium and potassium. The cross sections obtained in this approximation, which is simpler than the Born-Oppenheimer approximation, are compared with other theoretical and with experimental results. On the basis of this comparison it is suggested that the wave functions, on which the calculation is based, may form an acceptable first approximation in a more detailed variational treatment.