Calculation of complex band structure for plane-wave nonlocal pseudopotential Hamiltonian

We present a practical approach to calculate the complex band structure of an electrode for quantum transport calculations. This method is designed for plane wave based Hamiltonian with nonlocal pseudopotentials, although it can be used for any Hamiltonian that has a large (>100,000) basis set. Our method is particularly useful for the auxiliary periodic boundary condition transport calculation. The complex band structures of copper and gold nanowires, and bulk gold electrodes are presented. The nanowire wave functions are analyzed using effective mass pictures.