Transferability of self-energy correction in tight-binding basis constructed from first principles.

Abstract

We demonstrate in this work the transferability of self-energy (SE) correction (SEC) of Kohn-Sham (KS) single particle states from smaller to larger systems, when mapped through localized orbitals constructed from the KS states. The approach results in a SE corrected TB framework within which the mapping of SEC of TB parameters is found to be transferable from smaller to larger systems of similar morphology, leading to a computationally inexpensive approach for the estimation of SEC in large systems with reasonably high accuracy. The scheme has been demonstrated in insulating, semiconducting, and magnetic nanoribbons of graphene and hexagonal boron nitride, where the SEC tends to strengthen the individual π bonds, leading to transfer of charges from the edge to bulk. Additionally, in magnetic bipartite systems, the SEC tends to enhance inter-sublattice spin separation. The proposed scheme thus promises to enable the estimation of SEC of bandgaps of large systems without the need to explicitly calculate the SEC of KS single particle levels, which can be computationally prohibitively expensive.