Energetics of pairs and seven membered bundles formed by achiral as well as chiral carbon nanotubes is explored. The applied model Hamiltonian consists of a tight binding intratube part, an intermolecular hopping term, and a Lennard-Jones pair potential. Heterochiral aligned tube pairs are found the most stable energetically. Rotation of tubes around the tube axis in an aligned pair of identical tubes requires the smallest energy input if a cog-wheel rotation (disrotation) is exercised for heterochiral and achiral pairs or anti-cog-wheel rotation (conrotation) for a homochiral pair. Energetic preference for disrotation in heterochiral identical pairs manifests even for short (several nanometer long) tubes. Conrotation of homochiral pairs is hindered by end effects and becomes favorable only if modeling long (infinite) identical tubes. Among achiral tubes, those that possess a C3n axis with odd n are shown to form close-packed bundles in an energetically optimal way. Similarly, among achiral tubes those having a C3n axis, n either even or odd can form an energetically favorable close-packed bundle.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - May 12 2006|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics