The atomic and electronic structure of the (¯112) Σ3 boundary in diamond was examined using the density-functional theory with the plane-wave pseudopotential method. Boundary states lower than the bulk conduction-band minimum were observed in the reconstructed structure without rigid-body translation, consistent with recent high-resolution transmission electron microscopy observations. These gap states were attributed to the weak reconstructed bonds largely stretched along [110]. It was concluded that the experimentally observed small line below the σ* line in electron energy loss spectroscopy of this boundary corresponds to the gap states of the stretched bonds. The origins of the appearance of the structure without rigid-body translation in spite of its high energy in diamond were discussed.

Gap States due to Stretched Bonds at the (112) Σ3 Boundary in Diamond. H.Sawada, H.Ichinose, M.Kohyama: Journal of Physics - Condensed Matter, 2007, 19[2] 026223 (9pp)