Novel Silicon-Carbon Nanostructures: Electronic structure study on the stability of Si60C2n Clusters.

The formalism of generalized gradient approximation to density functional theory has been used to study the electronic and geometric structures of Si$_{60}$C$_{2n }$fullerene-like nanostructures. In our previous work, we have shown that the additions of carbon atoms increase the stability of smaller silicon cages [1]. In this talk, we will present our results on the addition of two and four carbon atoms on the surface of the Si$_{60}$ cages by substitution as also inside the cage at various symmetry orientations. Full geometry optimizations have been performed using the Hay-Wadt basis set without any symmetry constraints using the Gaussian 03 suite of programs [2]. Binding energies, ionization potentials, electron affinities and the ``band'' gaps of the stable silicon-carbon fullerene like nanostructures will be presented and discussed in detail. In general, we find that the optimized silicon-carbon fullerene-like cages have increased stability compared to the bare Si$_{60 }$cage. Possibilities of adding larger carbon clusters to the Si$_{60 }$structure will also be discussed. *Work supported, in part, by the Welch Foundation, Houston, Texas (Grant No. Y-1525). [1] M. N. Huda and A. K. Ray, Phys. Rev. A \textbf{69}, 011201(R) (2004); Eur. Phys. J. D \textbf{31}, 63 (2004). [2] \textit{Gaussian 03}, M. J. Frisch \textit{et al}. Gaussian Inc., Pittsburgh, PA.