  We present results of electronic structure and transport calculations for
metallic interfaces, based on density functional theory and the non-equilibrium
Green's functions method. Starting from the electronic structure of smooth Al,
Cu, Ag, and Au interfaces, we study the effects of different kinds of interface
roughness on the transmission coefficient and the I-V characteristic. In
particular, we compare prototypical interface distortions, including vacancies
and metallic impurities.
