A theoretical study on the geometrical features of finite-length carbon nanotubes capped with fullerene hemisphere

The structures of the finite-length (5,5) and (9,0) carbon nanotubes capped with fullerene hemisphere are analyzed by quantum chemical calculations at the B3LYP DFT level of theory. DFT calculations demonstrate that the geometries of the armchair tubes depend on the number of cyclic cis-polyene chains lined up along the tube axis, whereas the zigzag tubes consist of Kekulé-type networks in the cylinder, the geometries being independent of the number of component cyclic trans-polyene chains.