Description of band structures of armchair nanotubes using the symmetry-adapted linear augmented cylindrical wave method

Using a symmetry adapted linear augmented cylindrical wave method the total band structures and the densities of state of the armchair single walled carbon nanotubes (SWNTs) (n,n) with 4 <= n <= 20, n = 30, 40, 60, and 100 are calculated. The approximations are made in the sense of muffin-tin potentials and density functional theory only. The electronic stages are presented as the functions of two quantum numbers, namely, the continuous wave vector k corresponding to the screw symmetry operations and an integer rotational quantum number L between 0 and n-1. An account of rotational and helical symmetry properties of the armchair SWNTs and particularly an introduction of the quantum number L permit to elaborate a more detailed classification of the armchair SWNTs electronic states. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim