Ab initio calculations and scanning tunneling microscopy experiments of the Si(111)-(√7/x√3)-Pb surface -: art. no. 205403

We present first-principles electronic structure calculations combined with scanning tunneling microscopy experiments of the Si(111)-(root7xroot3)-Pb low-temperature structure. The ab initio calculations have been performed with two different atomic configurations. The structure proposed from x-ray data [C. Kumpf, Surf. Sci. 448, L213 (2000)] with 1.2 monolayer (ML) coverage is identified as the lowest energy one. The results from first-principles calculation are shown to agree well with experiment. The nature of bonding is discussed on the basis of the electronic density plots. The bonding is shown to be metallic within the lead overlayer.