Surface science lettersThe atomic geometry of Si(100)-(2×1) revisited

An R-factor analysis of published elastic low-energy electron diffraction (ELEED) intensity data from the (2×1) structure on Si(100) is presented. This analysis reveals the existence of a new asymmetric dimer structure which is compatible with ion-scattering measurements yet provides a description of the measured ELEED intensities which is improved relative to that afforded by structures proposed on the basis of prior ELEED intensity analyses. The structure is similar to but not identical with those predicted by several energy-minimization calculations. Consequently, our analysis resolves an extant incompatibility between ELEED and ion-scattering results as well as reveals the qualitative correctness of modern total-energy-minimization methods for surface-structure determinations