Green's function calculations on the complete valence ionization spectra of HF, HCl, HBr AND HI

The ionization spectra of the entire valence region are calculated for HF, HCl, HBr and HI. For the two ionization processes of lowest energy the common molecular orbital picture of ionization applies, whereas this picture breaks down for ionization from the inner valence α-orbital. For HF and HCl basis set effects on the calculated outer-valence ionization energies are investigated and accurate values are computed using large basis sets. The calculated inner valence ionization spectra are compared with recent (e, 2e)-measurements.