Atomic structure of the As-rich InAs(100)β2(2×4)surface

The surface atomic structure of the molecular-beam epitaxy prepared As-rich InAs(100) $(2\mathrm{}\times 4)$ reconstruction has been solved by synchrotron radiation surface x-ray diffraction. Analysis of a large set of nonequivalent in-plane diffraction peaks and seven out-of-plane rods yields the so-called $\beta 2-(2\times 4)$ model, a now recognized model for the As-rich GaAs(100) $(2\mathrm{}\times 4)$ structure. The structure comprises two As dimers in the top layer and one As dimer in the third layer below the first incomplete In layer.