Si adatom binding and diffusion on the Si(100) surface: Comparison of [ital ab] [ital initio], semiempirical and empirical potential results
- Department of Chemistry, BG-10, University of Washington, Seattle, Washington 98195 (United States)
- Department of Materials Science and Engineering, FB-10, University of Washington, Seattle, Washington 98195 (United States)
- Molecular Science Research Center, Pacific Northwest Laboratory, Richland, Washington 99352 (United States)
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
The binding energies and configurations for single Si adatoms on the Si(100) surface are investigated theoretically. Detailed comparisons between previously published and new calculations using classical potentials, semiempirical formulations, and density functional theory (DFT) are made. The DFT calculations used both the plane-wave-pseudopotential approach in a periodic slab geometry and the Gaussian-orbital based all-electron approach employing cluster geometries. In the local-density approximation excellent agreement between the cluster and slab results was obtained. Inclusion of gradient corrections to the exchange-correlation energy significantly improves absolute binding energies and changes relative energies by as much as 0.3--0.5 eV depending on the particular exchange-correlation functional used. Binding energies and relative energies obtained using the classical potentials disagree with the gradient corrected DFT energies at about the 0.6--0.9 eV level, and most find qualitatively different local minima from those found in the DFT calculations. The semiempirical approaches give results intermediate in quality between those of the classical potentials and the [ital ab] [ital initio] calculations. Analysis of the energies and binding site geometries provides insight into the shortcomings of some of the classical potentials.
- DOE Contract Number:
- FG06-91ER14224; AC06-76RL01830
- OSTI ID:
- 6720202
- Journal Information:
- Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 102:2; ISSN JCPSA6; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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