Cooper minima in the photoelectron dynamic spectra of small molecules : continuum multiple scattering X-alpha calculations

Results of multiple scattering X-alpha calculations are presented for the photoionization cross sections and angular parameter as a function of energy from one-tenth to about five Ry. Systems presented are: the noble gases, argon, krypton, and xenon; the halogen atoms, chlorine, bromine, and iodine; the hydrogen halides, HCl, HBr, and HI; and the homonuclear dihalogens, CI₂, Br₂, and I₂.

Particular attention is paid to energy regions of cross section minima (Cooper minima), and energy regions of cross section maxima (shape resonances). The effects of molecule formation on these cross section extrema are discussed.

The theoretical molecular results presented are compared with available experimental results.

A brief treatment of the concepts of angular resolved photoemission and a brief treatment of the multiple scattering X-alpha formalism are presented.