Conductance of molecular wires: Influence of molecule-electrode binding

We report on the effect of modifying the molecule-electrode binding interface of an alpha,alpha'-xylyl-dithiol molecular wire. We find that except for the length of the surface bond, the conductance is not affected by variations of the surface geometry. We also compare the conductance of different terminal atom-electrode metal combinations and find that the conductance is substantially larger when the wire is terminated by selenium rather than sulfur or oxygen. We also find that gold makes a better electrode than silver.