Are both symmetric and buckled dimers on Si(100) minima? Density functional and multireference perturbation theory calculations
We report a spin-unrestricted density functional theory (DFT) solution at the symmetric dimer structure for cluster models of Si(100). With this solution, it is shown that the symmetric structure is a minimum on the DFT potential energy surface, although higher in energy than the buckled structure. In restricted DFT calculations the symmetric structure is a saddle point connecting the two buckled minima. To further assess the effects of electron correlation on the relative energies of symmetric versus buckled dimers on Si(100), multireference second order perturbation theory (MRMP2) calculations are performed on these DFT optimized minima. The symmetric structure is predicted to be lower in energy than the buckled structure via MRMP2, while the reverse order is found by DFT. The implications for recent experimental interpretations are discussed.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director. Office of Science. Office of Basic Energy Sciences, SciDAC Computational Chemistry Program Contract DE-FG02-01ER403301 (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 836668
- Report Number(s):
- LBNL-53827; R&D Project: 403301; TRN: US0500772
- Journal Information:
- Journal of Chemical Physics, Vol. 119, Issue 20; Other Information: Submitted to Journal of Chemical Physics: Volume 119, No.20; Journal Publication Date: 22 Nov 2003; PBD: 29 Aug 2003
- Country of Publication:
- United States
- Language:
- English
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