We conducted a photoelectron spectroscopy and density-functional study on Sc2Sin (n = 2-6) clusters. The adiabatic detachment energies of Sc2Si2-6 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 Sc2Si3-6 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 Sc2Sin clusters is very weak comparing to the strong V-V interaction in V2Sin clusters. (C) 2010 Elsevier B.V. All rights reserved.