Theoretical study on the nucleation of Ag on Ge(0 0 1) surface

We present theoretical results of the density functional calculations on the adsorption of Ag on Ge(0 0 1) surface. The scanning tunneling microscopy (STM) images of each stable or metastable sites for the adsorption of a low coverage of Ag adatom are calculated. We suggested that the unit element of Ag islands in the STM is the Ag ad-dimer structures which are composed by the two coupling Ag atoms on Ge substrate.