612672.fig.002a
(a)
612672.fig.002b
(b)
Figure 2: (a) Cross-section of the hexagonal unit cell for the ( 5 , 5 ) nanotube in periodic boundary condition (PBC) calculations, given by blue hashed lines. (b) Side-view of the nanotube along the tube axis (the 𝑐 vector). Its supercell was given by blue-hashed lines.