Gold nanowires and their chemical modifications

Equilibrium structure, local densities of stales, and electronic transport in a gold nanowire made of a four-atom chain supported by two gold electrod es, which has been imaged recently by high-resolution electron microscopy, and chemical modification of the wire via the adsorption of a methylthiol m olecule,are investigated with ab initio local density functional simulation s. In the bare wire at the imaged geometry the middle two atoms dimerize, a nd the structure is strongly modified by the adsorption of the molecule wit h an accompanying increase of the ballistic conductance through the wire.