An armchair nanotube ([n.sub.1] = [n.sub.2]) subjected to a longitudinal tensile load [F.sub.T] is studied first.
For the armchair nanotube, the geometry relationships satisfy
The total axial force [F.sub.T] acting on the armchair nanotube can be related to bond force f as [F.sub.T] = 2[n.sub.1]f, so the force density over tube circumference can be defined as
The axial strain [[epsilon].sub.x] and circumferential strain [[epsilon].sub.[theta]] of armchair nanotube can be calculated as
The load-strain relationship for a zigzag tube can be calculated in a similar manner to the armchair nanotube described earlier.
But in the nanotubes, it had been predicted that the formation energies for divacancies in
armchair nanotubes are higher than in zigzag nanotubes.
Among the topics are synthesizing bowl-shaped and basket-shaped fullerene fragments with benzannulated enyne-allenes, experimental and calculated properties of fullerene and nanotube fragments, hemispherical geodesic polyarenes as attractive templates for the chemical synthesis of uniform-diameter
armchair nanotubes, conjugated molecular belts based on three-dimensional benzannulene systems, and toward fully unsaturated double-stranded cycles.
Thus the vectors (0,n) and (m,0) denote zig-zag nanotubes, the vectors (m,m) or (n,n) denote
armchair nanotubes and all other vectors correspond to chiral nanotubes.