Molecular dynamics simulations, on a scale comparable to experimental dimensions, were made of a peculiar surface reconstruction of the {105} facets which was responsible for the stability of Ge pyramids on Si(001). This was confirmed by ab initio total energy calculations for competing surface reconstructions, and a very satisfactory comparison of the corresponding charge density maps to scanning tunnelling microscopy measurements of the facets was found for both filled and empty states.

Critical Role of the Surface Reconstruction in the Thermodynamic Stability of {105} Ge Pyramids on Si(001). P.Raiteri, D.B.Migas, L.Miglio, A.Rastelli, H.von Känel: Physical Review Letters, 2002, 88[25], 256103 (4pp)