Finite-size modelling of electrodes for quantum transport calculations using k-space ab initio techniques

We present an efficient and easy-to-use numerical treatment to check the necessary size of metallic leads with respect to their quantum-transport properties. The suggested method works entirely in k-space and avoids complicated projections of ab initio band structures onto real-space tight-binding-like Hamiltonians. As an illustrative example, we apply the method to various low-dimensional Au chains and discuss our DFT-based studies with respect to convergence speed and relevance of structural relaxation.