Density functional calculations were used to study the formation of Stone-Wales defects in 4Å single-wall carbon nanotubes, which were synthesized using an AFI zeolite template. The minimum energy paths from perfect tubes to defect-containing ones were calculated by using the nudged elastic band method. It was found that the C-C bonds along the tube axis were more likely to be rotated than those bonds around the circumference. There was a marked chirality dependence of the formation barriers, which were found to be lower than that of graphite. The results raised questions as to the origin of the superconductivity observed in these 4Å tubes.

Energetics of Stone-Wales Defects in 4Å Carbon Nanotubes. Y.W.Wen, H.J.Liu, X.J.Tan, L.Pan, J.Shi: Journal of Nanoscience and Nanotechnology, 2010, 10[4], 2332-5