Two Centre Coulomb Potential Approximation

Abstract

An expression in the prolate spheroidal coordinates is given for the wave function of a slow electron scattered by a pair of point charges, Z a e and Z b e , fixed at a distance. The two centre Coulomb function is useful to approximate the wave function of a slow electron in the fields of diatomic molecular ions or polar molecules. By use of this approximation, the diffusion cross-section of electrons by polar molecules and the photoionization cross-section of hydrogen molecules near threshold energy are calculated. In these cases, the calculated cross-sections are about 1.3∼2 times smaller than the experimental ones.