Determination of local chirality in irregular single-walled carbon nanotubes based on individual iexagons

We develop a robust theoretical method for the determination of local chirality based on individual hexagons that compose single-walled carbon nanotubes (SWCNTs). The method and code are applied to various SWCNT-like irregular structures that are formed during the growth process. The local chiral index and its distribution are well defined for irregular structures as well as ideal structures of SWCNTs, and can be used to characterize any SWCNT-like irregular structures in terms of local chirality. The present method also permits monitoring the chirality of nanostructures during the growth process.