Quantum mechanical calculation of electronic band structure of helically periodic systems: a case of nanotubes and nanohelicenes

A method for obtaining electronic bands in the helical Brillouin zone based on results of high-level quantum mechanical calculations using CRYSTAL17 software package is considered. Using example a carbon nanotube chirality (4,1), preference comparison with translational shown. For nanohelicene, system which helically periodic only, states were obtained corresponding to structure closest energy minimum. In addition, evolution nanohelicene depending torsion distortions presented. Keywords: line symmetry groups, electron bands, nanotube.