Ab initiopseudopotential method for the calculation of conductance in quantum wires

We develop a method to incorporate the Kleinman-Bylander--type ab initio pseudopotential in the calculation of conductance in quantum wires using the Landauer formalism. This method is computationally efficient and mathematically stable; it does not involve singularity in inverting the transfer matrix. We also describe the ab initio nonlocal pseudopotential method to calculate the complex band structure that is required in the wave-function matching between the resistive material and the realistic metal probe. We present, as an example, the calculated conductance of the $(10,10)$ carbon nanotube with a pentagon-heptagon-pair defect in the low-temperature limit.