Photoelectron Velocity Map Imaging Spectroscopy Of The Beryllium Tetramer Anion Be₄^−

Beryllium is known to be a challenging test for even high level \textit{ab initio} methods due to high electron correlation contributions. There is fundamental interest in understanding how well computational methods can predict physical properties of beryllium containing molecules, but very little available experimental data on these molecules. We have continued in our exploration of beryllium molecules, and have acquired preliminary spectra for the beryllium tetramer, Be$_4$. In this talk we will present our work to date on Be$_4^-$, with comparisons to high level theory and the beryllium dimer