Eur. Phys. J. D 59, 399-406 (2010)
https://doi.org/10.1140/epjd/e2010-00139-y

Density-functional study of Si_nC_n (n = 10–15) clusters

State Key Laboratory of Silicon Materials and Department of Physics, Zhejiang University, Hangzhou, 310027, P.R. China

Corresponding author: ^a bzsong@css.zju.edu.cn

Received: 27 January 2010
Revised: 13 April 2010
Published online: 19 May 2010

Abstract

Density-functional theory with generalized gradient approximation for the exchange-correlation potential has been used to calculate the structural and electronic properties of Si_nC_n (n = 10–15) clusters. We find that the Si_nC_n clusters prefer cagelike structures. An extensive isomer search shows that the lowest-energy arrangements are those in which the silicon atoms and the carbon atoms form two distinct subunits. It is found that the carbon atoms favor to form fullerene-like structure due to the sp²-like bond. The silicon atoms are trying to cope with an unfavorable sp² environment, but distorted tetrahedra still show up somewhere of the cagelike structures. On the basis of the lowest-energy geometries obtained, the binding energy, HOMO–LUMO gap, Mulliken charge, ionization potential and electron affinity of the clusters have been computed and analyzed. An electronic charge transfer from the Si-populated to the C-populated regions is observed.