SinC13-n (n = 1 – 12) Clusters: An All-electron DFT Investigation

Abstract

The geometrical and electronic structures of Si_nC_13-n (n = 1 – 12) nanoclusters have been investigated using all-electron density functional theory (DFT) with the generalized gradient approximation (GGA). The binding energies, highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps, and the vibrational frequencies have been computed. We note that the binary clusters have a number of isomeric structures with lower symmetries and the stability of the clusters increases as the number of carbon atoms increases. As the number of silicon atoms increases, the lowest-energy structures of the Si_nC_13-n (n = 1 – 12) clusters transform from planar structures to three-dimensional structures. The HOMO-LUMO gaps of the lowest-energy structures indicate that with the exception of Si₆C₇ and Si₁₂C, the ground states are of high chemical stability and have the characteristics of semiconductors. In addition, the Mülliken populations show that there is significant charge transfer from the silicon atoms to the carbon atoms.