STUDY OF THE LOW-LYING STATES OF GE-2 AND GE-2(-) USING NEGATIVE-ION ZERO ELECTRON KINETIC-ENERGY SPECTROSCOPY

The low-lying states of Ge2 and Ge2- are probed using negative ion zero electron kinetic energy (ZEKE) spectroscopy. The ZEKE spectrum of Ge2- yields an electron affinity of 2.035±0.001 eV for Ge2, as well as term energies and vibrational frequencies for the low-lying states of Ge2- and Ge2. Specifically, we observe transitions originating from the anion 2Πu(3/2) ground state and 3Σ g+ excited state (Te=279±10 cm -1) to several triplet and singlet states of Ge2. Term values and vibrational frequencies are determined for the Ge2 3Σg+ ground state, the low-lying 3Πu excited state (Te=337 cm-1 for the 2u spin-orbit component), and the somewhat higher lying 1Δg, 3Σg+, and 1Πu states. We also determine the zero-field splitting for the X0g+ and 1g components of the 3Σg+ state and the splittings between the 2U, 1u, and 0u± spin-orbit components of the 3Πu state. Detailed comparisons are made with Si2 and Si2-. © 1995 American Institute of Physics.