Role of lattice registry in the full collapse and twist formation of carbon nanotubes

Abstract
The effect of interlayer lattice registry on the formation of fully collapsed single wall carbon nanotubes (SWCNTs) was studied via atomistic simulation. It was found that a fully collapsed SWCNT could adopt various structural morphologies, such as a straight ribbon, a warping ribbon, or even a twisted ribbon. Such structural formations depended on the degree of commensurance between the lattice structures of the adhering layers in a collapsed SWCNT, thus the chirality of the SWCNT. The modeling result was further corroborated with a simple analysis of the system energy difference among graphitic double layer structures with different interlayer lattice registry, and with the experimental observation of freestanding, twisted, and collapsed nanotubes.