Structural Derivative and Electronic Property of Armchair Carbon Nanotubes from Carbon Clusters

The structural derivative and electronic property of carbon nanotubes from carbon clusters were investigated by density functional theory (DFT), including armchair single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs). Results show that the carbon nanotubes (CNTs) can be obtained through layer-by-layer growth from the initial structure. The structural derivative processes are quantitatively described by monitoring changes in local configuration. Electronic properties show the energy gaps of finite SWCNTs and double-walled CNTs (DWCNTs) depending on their lengths. However, the band structures ofMWCNTs differ from those of SWCNTs; the band structures of DWCNTs (4, 4)@(8, 8), (5, 5)@(10, 10), and TWCNTs show metallicity, whereas those of (3, 3)@(6, 6) DWCNTs show a strong semiconductor characteristic. Analysis of the partial density of states shows that the diameters and walls of CNTs have no obvious effects on the distribution of total density of states near the Fermi level of SWCNTs and MWCNTs.