Generalization of the atomic RPA method for diatomic molecules: H2 photoionization cross-section calculation

The well-known procedure of atomic photoionization cross-section calculations in the random-phase approximation is generalized here for diatomic molecules. As an orthonormal zero-order basis set, the Hartree–Fock wavefunctions of the discrete and continuous spectrum are used; they are calculated in prolate spheroidal coordinates. The photoionization cross-section of the H2 molecule obtained by this method in the photon energy range from the ionization threshold up to 160 eV is in good agreement with experimental data.