Journal or Book Title
Journal of Chemical Physics
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 DFTpotential 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.
Copyright 2003 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
American Institute of Physics
Jung, Yousung; Shao, Yihan; Gordon, Mark S.; Doren, Douglas J.; and Head-Gordon, Martin, "Are Both Symmetric and Buckled Dimers on Si(100) Minima? Density Functional and Multireference Perturbation Theory Calculations" (2003). Chemistry Publications. 417.