Rolling vector, single walled carbon nanotubes

A single-walled carbon nanotube is often described as the result of seamless wrapping of a graphene sheet into a cylinder along the ( , m) roll-up vector,... 

Figure 18.1. AU single-walled carbon nanotubes can be described by the numbers (n, m) corresponding to a chiral vector (rollup vector) indicating the direction in which a graphene sheet is rolled and fused to yield a carbon nanotube.

Carbon nanotubes are classified as single-walled nanotubes (SWNTs) and multiwalled nanotubes (MWNTs). A SWNT can be visualized as a grapheme sheet that has been rolled into a hollow cylinder with ends caps. So the atomic structure of SWNT can be described by the chiral vector and the chiral angle 6 (see Fig. 23.5) given by Refs. [70-77] ... 

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