What is the ionization potential of silicon dimer?

Resonant two-photon ionization and laser-induced fluorescence spectra of the Si2 H 3Σu− ← X3Σg− transition are presented. The ionization behavior of several H 3Σu− vibrational levels is investigated using KrF excimer and Nd: YAG laser fourth harmonic radiation. The results of these studies are employed to tightly bracket the silicon dimer ionization potential (7.9–8.1 eV). This evaluation is discussed in relation to previous estimates of the Si2 ionization potential reported in the literature.