The zone-folding method is a widely used technique for computing the electronic structure of carbon nanotubes as well as of other type nanotubes. Within this method the electronic dipersion of a nanotube is calculated from that of the corresponding 2D sheet (e.g. graphene). In this talk the problem of curvature based discrepancy between direct calculations from the tubular structure and from the related 2D sheets is examined. [1] Curvature effects of boron and carbon nanotubes of different diameters and chiralities are systematically quantified using the density functional based tight-binding method. The difference between both calculation methods can also be considered as the error of the zone-folding method. For each nanotube we quantify this error by calculating the standard deviation of the band energies and the maximal relative deviation between the derived ballistic currents. Our results indicate that quantitative predictions made using the zone-folding method may have non-negligible error.

[1] Bezugly, Eckert, Kunstmann, Kemmerich, Meskine, Cuniberti; submitted