The structure of the hydrogen terminated, $(2\mathrm{}\times 1)$ reconstructed diamond (100) surface has been investigated by low-energy electron-diffraction (LEED) intensity versus energy $\left[I\right(E\left)\mathrm{}\right]$ measurements in combination with tensor LEED calculations. It has been found that the surface corresponds to the formation of symmetric dimers on the top C layer, with a dimer length of 1.60 Å. The top layer shows slight inward relaxation; the interlayer spacing between the first and second C layers reduces to 0.81 Å, which corresponds to an ∼7% contraction compared to the bulk value. The structural details of the first four carbon layers have been determined and are compared to those given by theoretical calculations.

• Received 31 August 1998

DOI:https://doi.org/10.1103/PhysRevB.59.10347