The structure of diamond lattice (111) surfaces and X-ray diffraction.

We present the general physical and chemical principles expected to influence the covalent bonding in the surface structure of diamond-like crystals when bounded by vacuum. The common observation of a change of surface symmetry ("reconstruction") can be exploited by high intensity sources of x-ray synchrotron radiation to yield crystallographic information. A structural analysis of the InSb(111) surface provides detailed chemical information that allows us to distinguish between different models of reconstruction. Ge(111) and Si(111) surfaces and the forces governing their structure are also discussed.