  Investigating topological effects in materials requires often the modeling of
material systems as a whole. Such modeling restricts system sizes, and makes it
hard to extract systematic trends. Here, we investigate the effect of M\"obius
topology in the electronic structures of armchair graphene nanoribbons. Using
density-functional tight-binding method and minimum-cell simulations through
revised periodic boundary conditions, we extract electronic trends merely by
changing cells' symmetry operations and respective quantum number samplings. It
turns out that for a minimum cell calculation, once geometric and magnetic
contributions are ignored, the effect of the global topology is unexpectedly
short-ranged.
