Angular Distribution of Molecular Photoelectrons

The nonrelativistic differential cross sections for photo-ionization of molecules are derived and are worked out in detail for systems with random orientation. The more important contributions due to electric dipole, electric quadrupole, magnetic dipole, and two-photon (nonresonant) absorption have been included. Processes such as vibrationally induced auto-ionization have been discussed. The significance of these results with regard to the design and interpretation of photo-ionization experiments is also considered. The angular distribution of photoelectrons from ${\mathrm{H}}_2$ is calculated as an example.