The current flow for a benzene-1,4-dithiol molecule between two Au contacts is computed. For most configurations considered, the computed current is an order of magnitude larger than experiment, as found by other groups. When the benzene-1,4-dithiol is bonded to the top of an fee cluster of Au atoms, the current flow is significantly reduced, bringing it into better agreement with experiment. This represents an alternative to the previously proposed two molecule mechanism, as explanation of the experimental results. (C) 2003 Elsevier Science B.V. All rights reserved.