bandstrucutre of graphene

[paramjot]

when we take bandstructure of the graphene sheet from the database ( with hexagonal unit cell) it shows the proper conical band structure at k point but when we design graphene nanoribbon ( cubic unit cell) from nanoribbon plugin it doesn't give the same curve. is there any way to get proper conical curves as shown by graphene sheet .

[Petr Khomyakov]

You change not only the unit cell of graphene in the direct space, but also in the reciprocal space, i.e.,  Brillouin zone (BZ) is no longer hexagonal, so you should search in the new BZ for what was the K-point in the original hexagonal cell.

Also, if this nanoribbon has a finite width with edges, the system may have a band gap.