The Photoionization of H2 and the Spatial Correlation between Electrons

The photoionization of H 2 by photons of sufficiently short wave length produces the molecular ion H 2 + as well as the atomic ion H + . The relative yield H + /H 2 + has been calculated as the function of energies of photons. The description of the ground state of H 2 is given by the superpositon of two configurations: σ g 2 +λσ u 2 , taking account of the spatial correlation between electrons, while those of H 2 + by the linear combinations of Wang type atomic orbitals. The results show that the relative yield curve has a plateau in the high-energy range and its height is essentially proportional to λ 2 . The various approximations used in our calculation (Franck Condon approximation, Born approximation, dipole velocity approximation, the neglect of possibility of production of H 2 + and H + through autoionization and multiple ionization etc.) have been carefully discussed. The velocity distribution of the ejected protons has also been calculated according to the Franck Condon principle.