SILICON-NIOBIUM BLOCKS FOR THE DESIGNING OF NEW NANOSTRUCTURES
DOI:
https://doi.org/10.17308/kcmf.2018.20/511Keywords:
DFT, atomic clusters, electronic structure, nanostructures.Abstract
This paper presents the calculation results of the spatial structure and electron energy spectrum of the anionic silicon-niobium clusters (n = 10, 12, 14, 16). A comparison of the calculated total density of electronic states with experimental photoelectron spectra allowed us to determine the structure of the clusters. The calculations were carried out within the density functional theory (DFT) framework where the Becke’s three-parameter and Lee-Yang-Parr’s gradient-corrected correlation hybrid functional (B3LYP) and 6-311+G(d) basis sets were used for the silicon atoms and DGDZVP basis sets were used for the niobium atom for a structural optimization as implemented in GAUSSIAN 09 (G09).
The major isomer of the cluster is a pentagonal bipyramid with a niobium atom in one of the vertices and with four additional silicon atoms. The major isomer of the cluster is a distorted hexagonal prism with an incapsulated niobium atom. The hexagonal anti-prism isomer and the prolate isomer are also stable. The segment of the prolate isomer are pentagonal bipyramids, with a shared niobium atom at the basis. The major isomer of the 0 cluster is a fullerene-like polyhedron with an encapsulated niobium atom. The prolate isomer of this cluster is also stable, but has a lower average binding energy than prismatic isomers. The major isomer of the cluster has a fullerene-like structure in the form of a polyhedron with eight pentagonal side edges and rhombic bases. The prolate isomer of this cluster is also stable, but has a lower average binding energy than prismatic isomers.
Thus, two types of structures possible for anionic silicon-niobium clusters are endohedral and prolate structures. Endohedral structures are more stable and their calculated electron spectra are more consistent with experimental photoelectron spectra.
ACKNOWLEDGEMENTS
The presented calculations were made with the help of the computing resources of the Supercomputer Centre of Voronezh State University.
