Theoretical studies of photoionization cross sections and angular distributions for the hydrogen molecule. [20 to 40 eV]

Theoretical studies of photoionization cross sections and angular distributions are reported for the ground state of the hydrogen molecule in the photon energy range 20--40 eV. Results are obtained using an integral equation technique recently developed by Chapman and Hayes. The method employs a partial-wave expansion for the continuum wavefunction to generate a set of coupled equations which are solved exactly using an integral equation technique. Single-center expansions are used for the initial and final electronic wavefunctions and exchange is treated iteratively. The results agree rather well with earlier studies of Kelly, of Ritchie, and of Hirota. Studies of the dependence of the differential cross section on molecular orientation are reported. These studies are of potential interest as a simple model for photoionization of a molecule adsorbed on a surface.