The nanotube has
a spiral base as can be seen in Fig. 3. There are two walls on
the left side and three on the right—the nanotube is made by a
rolling 2D sheet. The first step in our computer simulation
was to build amodel. The radius of nanotube is one necessary
parameter of the model and it could be estimated from the
HRTEM image. The inner diameter of the nanotube is 53.8 Å.
The second important parameter of the model is the distance
between walls.