Cu n Si 12 ( n = 30, 38, and 60): A series of silicide cages with high content of TM atoms

Abstract

A series of silicide cages with high content of transition metal atoms, CunSi12 (n = 30, 38, and 60) clusters, have been systematically investigated in the framework of density functional theory. Among them, Cu30Si12 with a higher Eb and a lager HOMO-LUMO gap has been discussed in detail. To be specific, the hollow cage-like structure Cu30Si12, which adopts an Ih-symmetry, can be described as the combination of 12 Cu5Si. Molecular dynamics simulations and vibrational frequency analysis have been conducted to verify its stability. Electron density analysis, natural bond orbitals analysis, and partial density of states analysis have been done to explore the binding characters of Cu30Si12. The results indicate that the σ bonds between Cu and Si atoms are of great importance for structural stability. More importantly, on one hand, CunSi12 (n = 30, 38, and 60) can encapsulate atoms or molecules to regulate their properties. On the other hand, CunSi12 (n = 30, 38, and 60) may be rather tempting for the further semiconductor devices due to the existence of silicon.