Towards a theoretical description of molecular junctions in the Coulomb blockade regime based on density functional theory

Nonequilibrium Green's function techniques (NEGF) combined with density functional theory (DFT) calculations have become a standard tool for the description of electron transport through single molecule nanojunctions in the coherent tunneling regime. However, the applicability of these methods for transport in the Coulomb blockade (CB) regime is still under debate. Here we present NEGF-DFT calculations performed on simple model systems in the presence of an effective gate potential. The results show that (i) the CB addition energies can be predicted with such an approach with reasonable accuracy and (ii) neither the magnitude of the Kohn-Sham gap nor the lack of a derivative discontinuity in the exchange-correlation functional represent a problem for this purpose.