First-principle study of silicon cluster doped with rhodium: Rh2Sin (n = 1–11) clusters

Abstract

The geometries, stabilities and electronic properties of rhodium-doped silicon clusters Rh2Sin (n = 1–11) have been systematically studied by using density functional calculations at the B3LYP/GENECP level. The optimized results show that the lowest-energy isomers of Rh2Sin clusters favor three-dimensional structures for n = 2–11. Based on the averaged binding energy, fragmentation energy, second-order energy difference and HOMO-LUMO energy gap, the stabilities of Rh2Sin (n = 1–11) clusters have been analyzed. The calculated results suggest that the Rh2Si6 cluster has the strongest relative stability and the doping with rhodium atoms can reduce the chemical stabilities of Sin clusters. The natural population and natural electron configuration analysis indicate that there is charge transfer from the Si atoms and 5s orbital of the Rh atoms to the 4d and 5p orbitals of Rh atoms. The analysis of electron localization function reveal that the Si–Si bonds are mainly covalent bonds and the Si–Rh bonds are almost ionic bonds. Moreover, the vertical ionization potential, vertical electron affinity, chemical hardness, chemical potential, vibrational spectrum and polarizability are also discussed.