Interplay between geometrical and electronic stability of neutral and anionic Cu

DFT and MP2 calculations were performed to compare the relative stability of neutral and anionic Cu13 isomers. Unlike some other 13-atom transition metal clusters, both the neutral and anionic icosahedral Cu13 clusters were found less stable than their layered isomers, resulting from stronger inter-layer bonding in the layered structures. A comparative analysis on the electronic configurations of Cu13, Na13 and Sc13 reveals weak d-s-p hybridization in the Cu13 isomers, similar to the weak s-p hybridization in Na13, but in contrast to the strong s-d hybridization in Sc13. The computed ionization potential of the most stable neutral Cu13 and the vertical detachment energy of the most stable anionic Cu13 are in good agreement with the measurements