title: A Natural Helical Crystal Lattice Model for Carbon Nanotubes.
abstract: We propose a novel helical crystal lattice model for chiral and achiral carbon nanotubes (CNTs) where the unit cell and the helical crystal vector are defined in a unique and systematic manner for arbitrary CNTs. The small unit cell of this helical crystal lattice leads to a natural and convenient description of the electronic structure of chiral CNTs. Also, using this model, the degenerate frontier Bloch wave functions at the Γ point can be conveniently chosen by their symmetry properties. In particular, the contour of the Bloch wave functions at the Fermi level can be easily predicted for all metallic CNTs.
authors.affiliation: Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan 11677.
authors.forename: Elise Y
authors.initials: EY
authors.lastname: Li
authors.affiliation: Theory and Simulations of Materials (THEOS), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Nicola
authors.initials: N
authors.lastname: Marzari