Quantum chemical calculation studies of PdnSi12 (n = 1–3) clusters: effects of doping Pd atoms on the structural and electronic properties

Abstract

ABSTRACTStructural and electronic properties of silicon clusters doped with different number of palladium atoms, PdnSi12 (n = 1–3), are investigated using quantum chemical calculations. The most stable structures of , PdSi12, and are found to be a distorted Si12 hexagonal prism with a Pd atom encapsulated into Si12 cage. Further addition of the second and third Pd atoms leads to different structural evolutions for anionic, neutral, and cationic Pd2Si12 (n = 2–3) clusters. The most stable structures of both and Pd2Si12 adopt a Si12 bicapped pentagonal prism with an edge-capping Pd atom and another Pd atom at the centre, while that of has a distorted Si12 hexagonal prism with a Pd atom at the centre and another Pd atom edge-capping one vertical Si−Si bonds of Si12 cage. Interestingly, the most stable structure of adopts a D3h symmetric tritruncated trigonal bipyramid. Pd atoms in anionic, neutral, and cationic PdnSi12 (n = 2–3) clusters are found to have very weak interactions. Natural population analysis suggests that negative charges transfer from Si12 frameworks to Pd atoms. Furthermore, the D3h symmetric tritruncated trigonal bipyramid of exhibits significant aromaticity and σ plus π double bonding characters.