Structure and vibrational spectra of low-energy silicon clusters
- 1 December 1997
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review A
- Vol. 56 (6), 4890-4898
- https://doi.org/10.1103/physreva.56.4890
Abstract
We have identified low-energy structures of silicon clusters with 9 to 14 atoms using a nonorthogonal tight-binding method (TB) based on density-functional theory (DF). We have further investigated the resulting structures with an accurate all-electron first-principles technique. The results for cohesive energies, cluster geometries, and highest occupied to lowest unoccupied molecular orbital (HOMO-LUMO) gaps show an overall good agreement between DF-TB and self-consistent-field (SCF) DF theory. For Si and Si we have found equilibrium structures, whereas for Si Si and Si we present clusters with energies close to that of the corresponding ground-state structure recently proposed in the literature. The bonding scheme of clusters in this size range is different from the bulk tetrahedral symmetry. The most stable structures, characterized by low energies and large HOMO-LUMO gaps, have similar common subunits. To aid in their experimental identification, we have computed the full vibrational spectra of the structures, along with the Raman activities, IR intensities, and static polarizabilities, using SCF-DF theory within the local-density approximation (LDA). This method has already been successfully applied to the determination of Raman and IR spectra of silicon clusters with 3–8, 10, 13, 20, and 21 atoms.
Keywords
This publication has 37 references indexed in Scilit:
- Density-functional-based predictions of Raman and IR spectra for small Si clustersPhysical Review B, 1997
- Vibrational signatures for low-energy intermediate-sized Si clustersPhysical Review B, 1996
- Improved nonorthogonal tight-binding Hamiltonian for molecular-dynamics simulations of silicon clustersPhysical Review B, 1994
- Transferable tight-binding models for siliconPhysical Review B, 1994
- Shape of small silicon clustersPhysical Review Letters, 1993
- Density functional study of the bonding in small silicon clustersThe Journal of Chemical Physics, 1992
- Electronic structures and photoelectron spectra of Si−3 and Si−4The Journal of Chemical Physics, 1992
- Generating Transferable Tight-Binding Parameters: Application to SiliconEurophysics Letters, 1989
- Bonding and stabilities of small silicon clusters: A theoretical study of Si7–Si1The Journal of Chemical Physics, 1988
- Equilibrium Structures and Finite Temperature Properties of Silicon Microclusters fromab initioMolecular-Dynamics CalculationsPhysical Review Letters, 1988