An accurate and efficient self-consistent approach for calculating electron transport through molecular electronic devices: including the corrections of electrodes

A self-consistent ab initio approach for calculating electron transport through molecular electronic devices is developed. It is based on density functional theory (DFT) calculations and the Green's function technique employing a finite basis of local orbitals. The device is rigorously separated into the extended molecule region and the electrode region. In the DFT part calculating the Hamiltonian matrix of the extended molecule from its density matrix, the electrostatic correction induced by electrodes and the exchange–correlation correction due to the spatial diffuseness of localized basis functions are included. Our approach is efficient and accurate, with a controllable error to deal with such open systems. A one-dimensional infinite gold monatomic chain, whose electronic structure can be known from conventional DFT calculations with periodic boundary conditions (PBCs), is employed to validate the accuracy of our approach. With both corrections, our result for the gold chain at equilibrium is in excellent agreement with the PBC DFT result. We find that, for the gold chain, the exchange–correlation correction is more significant than the electrostatic correction.