Density Functional Study of the Photodetachment Spectra of Zinc and Calcium Cluster Anions.

The structure and electronic states of zinc cluster anions Zn$_{2}$ through Zn$_{9}$ and calcium cluster anions from Ca$_{2}$ through Ca$_{19}$ were optimized within the hybrid density functional approach. Based on these results, the photoelectron detachment spectra of Zn$_{2}$ through Zn$_{6}$ and of Ca$_{2}$ through Ca$_{6}$ anions were determined. Additionally, the electron affinity of Zn$_{N}$ (N up to 9) and of Ca$_{N }$(N up to 19) was calculated within the same approximation. Both the calculated electron affinities and theoretical photoelectron binding energies are in very good agreement with experiment. Theoretical predictions for Zn$_{3}$, Ca$_{2}$ and Ca$_{4}$ anions display additional electron detachment binding energies that are not present in the published experimental data.