Cluster-based density-functional approach to quantum transport through molecular and atomic contacts

We present a cluster-based approach to model charge transport through molecular and atomic contacts. The electronic structure of the contacts is determined in the framework of density functional theory, and the parameters needed to describe transport are extracted from finite clusters. A similar procedure, restricted to nearest-neighbor interactions in the electrodes, has been presented by Damle et al (2002 Chem. Phys. 281 171). Here, we show how to systematically improve the description of the electrodes by extracting bulk parameters from sufficiently large metal clusters. In this way, we avoid problems 7 Author to whom any correspondence should be addressed. New Journal of Physics 10 (2008) 125019 1367-2630/08/125019+28$30.00 © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft