We have developed a pair-potential approach for the evaluation of van der Waals interaction between carbon nanotubes in bundles. Starting from a continuum model, we show that the intertube modes range from 5cm−1 to 60cm−1. Using a non-orthogonal tight-binding approximation for describing the covalent intra-tube bonding in addition, we confirme a slight chiral dependance of the breathing mode frequency and we found that this breathing mode frequency increase by ∼ 10 % if the nanotube lie inside a bundle as compared to the isolated tube.
@article{arxiv.cond-mat/9906424,
title = {van der Waals interaction in nanotube bundles : consequences on vibrational modes},
author = {L. Henrard and E. Hernandez and P. Bernier and A. Rubio},
journal= {arXiv preprint arXiv:cond-mat/9906424},
year = {2009}
}