A first-principles divide-and-conquer approach for electronic structure of large systems andits application to graphene nanoribbons

Abstract

We demonstrate an efficient and accurate first-principles method to calculatethe electronic structure of a large system using a divide-and-conquer strategybased on localized quasi-atomic minimal basis set orbitals recently developed.Tight-binding Hamiltonian and overlap matrices of a large system can be constructed byextracting the matrix elements for a given pair of atoms from first-principlescalculations of smaller systems that represent the local bonding environment ofthe particular atom pair. The approach is successfully applied to the studies ofelectronic structure in graphene nanoribbons. This provides a promising wayto do the electronic simulation for large systems directly from first principles.