A quantum chemistry approach for current-voltage characterization of molecular junctions

Based on the elastic-scattering Green's function theory, we have developed an approach to characterize the electron transport process in molecular devices, thereby allowing descriptions of the couplings between the molecule and metals at the hybrid density functional theory level. Two molecular devices with benzene-1,4-dithiol and alpha,alpha'-xylyl dithiol molecules embedded between two gold electrodes have been studied at the correlated hybrid density functional theory level. The calculated current-voltage characteristics are in very good agreement with existing experimental results, indicating the vital importance of the electron correlation effects in the electron transport. We have also examined the existence of one electron reduction and its effects on the current-voltage characteristics.