Application of Green's functions to excitations accompanying photoionization in atoms and molecules

The method of Green's one-particle functions is used to explain excitations with simultaneous ionization in atoms and molecules. The relative intensities of satellite lines in the photoelectron spectra, which arise due to excitations accompanying photoionization, are found to be simply related to the pole strengths of the Green's functions. For the water molecule many such satellite lines are calculated to be in the region of 25–80 eV binding energy.