Comparative theoretical study of single-wall carbon and boron-nitride nanotubes

We present a comprehensive comparative study of properties of BN and C nanotubes using a full potential linear combination of atomic orbitals approach, as well as a planewave pseudopotential method. This paper covers our results on the structural, mechanical, vibrational, and electronic properties, examining in detail the effects of intertube coupling. Structural aspects and mechanical properties are discussed and compared in BN and C nanotubes, and to experiment. Upshifts in the values of the radial breathing modes, due to intertube coupling, are found to be small and systematic, about 2% in zigzag nanotubes, and varying from 2 to 7 % in armchair tubes, for both materials. Finally, the effects of intertube interactions on the van Hove singularities are discussed.