Nanotube field of ${\mathrm{C}}_{60}$ molecules in carbon nanotubes: Atomistic versus continuous approach

Nanotube field of $C_{60}$ molecules in carbon nanotubes: Atomistic versus continuous approach

B. Verberck and K. H. Michel

Phys. Rev. B 74, 045421 – Published 21 July 2006

Abstract

We calculate the van der Waals energy of a $C_{60}$ molecule when it is encapsulated in a single-walled carbon nanotube with discrete atomistic structure. Orientational degrees of freedom and longitudinal displacements of the molecule are taken into account, and several achiral and chiral carbon nanotubes are considered. A comparison with earlier work where the tube was approximated by a continuous cylindrical distribution of carbon atoms is made. We find that such an approximation is valid for high and intermediate tube radii; for low tube radii, minor chirality effects come into play. Three molecular orientational regimes are found when varying the nanotube radius.