Photoelectron Spectroscopy of Alkali Metal Cluster Anions

ABSTRACf. We present the photoelectron (photodetacment) spectra of K2:-19 recorded using 2.540 eV photons. These spectra are highly structured, providing a wealth of information about the electronic structure of alkali metal clusters, including adiabatic electron affinities and electronic spliuings for each size. Spectral assignments have been made with guidance from theory. For the smaller cluster sizes, detailed assignments of the spectra were aided by ab initio quantum chemical calculations. For the larger clusters, assignments were guided by a simple shell model. A substantial correlation is found between the predicted shell model energy levels and the observed patterns and spacings in the spectra.