title: The vibration properties of the (n,0) boron nitride nanotubes from ab initio quantum chemical simulations.
abstract: The vibration spectrum of single-walled zigzag boron nitride (BN) nanotubes is simulated with an ab initio periodic quantum chemical method. The trend towards the hexagonal monolayer (h-BN) in the limit of large tube radius R is explored for a variety of properties related to the vibrational spectrum: vibration frequencies, infrared intensities, oscillator strengths, and vibration contributions to the polarizability tensor. The (n,0) family is investigated in the range from n = 6 (24 atoms in the unit cell and tube radius R = 2.5 Å) to n = 60 (240 atoms in the cell and R = 24.0 Å). Simulations are performed using the CRYSTAL program which fully exploits the rich symmetry of this class of one-dimensional periodic systems: 4n symmetry operators for the general (n,0) tube. Three sets of infrared active phonon bands are found in the spectrum. The first one lies in the 0-600 cm(-1) range and goes regularly to zero when R increases; the connection between these normal modes and the elastic and piezoelectric constants of h-BN is discussed. The second (600-800 cm(-1)) and third (1300-1600 cm(-1)) sets tend regularly, but with quite different speed, to the optical modes of the h-BN layer. The vibrational contribution of these modes to the two components (parallel and perpendicular) of the polarizability tensor is also discussed.
authors: Dipartimento di Chimica and Centre of Excellence NIS (Nanostructured Interfaces and Surfaces), Università di Torino, via Giuria 5, IT-10125 Torino, Italy.
authors: A
authors: A
authors: Erba
authors: M
authors: M
authors: Ferrabone
authors: J
authors: J
authors: Baima
authors: R
authors: R
authors: Orlando
authors: M
authors: M
authors: Rérat
authors: R
authors: R
authors: Dovesi
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry*; D011789:Quantum Theory; D014732:Vibration
chemical_list: D001896:Boron Compounds; C017282:boron nitride