  Structural and electronic properties, including deformation, magnetic moment,
Mulliken population, bond order as well as electronic transport properties, of
zigzag graphene nanoribbon (ZGNR) with Co adatom on hollow site are
investigated by quasi-atomic minimal basis orbits (QUAMBOs), a first-principles
tight binding (TB) scheme based on density functional theory (DFT), combined
with non-equilibrium Green's function. As for electronic transport, below Fermi
level the transmission is strongly suppressed and spin-dependent as a result of
magnetism by Co adatom adsorption, while above Fermi level the transmission is
slightly distorted and spin-independent. Due to local environment dependence of
QUAMBOs-TB parameters, we construct QUAMBOs-TB parameters of ZGNR lead and ZGNR
with Co adatom on the hollow center site by divide-and-conquer approach, and
well reproduce the electronic transmission behavior. Our QUAMBO-NEGF method is
a new and promising way for electronic transport in large-scale system.
