A combined density functional theoretical and photoelectron spectroscopic study of Ge2O2

We study Ge2O2 and Ge2O2 2 with density functional theory ~DFT! and photoelectron spectroscopy ~PES!. We find that Ge2O2 is a rhombus ~D2h), closed-shell molecule with a large HOMO-LUMO gap. The PES spectrum of Ge2O2 2 is obtained at four detachment photon energies: 1064, 532, 355, and 266 nm. Vibrational structure is resolved at the lowest photon energy with a single progression and a frequency of 400 ~60! cm. The experimental adiabatic electron affinity is obtained to be 0.625 ~0.050! eV for Ge2O2. The calculated vertical and adiabatic electron affinities and the HOMO-LUMO gap are in good agreement with the experimental values. The calculated totally symmetric vibrational mode of Ge2O2 ~335 cm ! is in reasonable agreement with the observed vibration and represents a Ge–Ge breathing motion. © 1995 American Institute of Physics.