Photoelectron spectroscopy and density-functional study of Sc 2Si n− ( n = 2–6) clusters

Abstract

We conducted a photoelectron spectroscopy and density-functional study on Sc 2Si n − ( n = 2–6) clusters. The adiabatic detachment energies of Sc 2Si 2–6 − were estimated to be 1.42 ± 0.08, 1.37 ± 0.08, 1.33 ± 0.08, 1.9 ± 0.2, and 2.0 ± 0.2 eV respectively from their photoelectron spectra. Comparison of theoretical and experimental results indicates that each of these clusters has more than one isomer in the experiments. In the most stable structures of Sc 2Si 3–6 − clusters, the silicon atoms form an n-membered silicon ring, and the two Sc atoms cap to the opposite sides of the ring. The Sc–Sc interaction in Sc 2Si n − clusters is very weak comparing to the strong V–V interaction in V 2Si n − clusters.