A DFT study of carbon nanobuds

In the framework of the density functional theory (DFT) calculations, we present a first time investigation of the properties of four kinds of configurations of carbon nanobuds (CNBs) in which a perfect or defective C60 molecule attaches covalently on the surface of an armchair single-walled carbon nanotube (SWCNT). Chemical shielding (CS) parameters were calculated for the optimized structures. Our results indicate that carbon nanobuds have different values of formation energy, band gap energy, dipole moment, charge transfer and chemical-shielding isotropy (CSI), which result from the many covalent combinations of the fullerenes with the carbon nanotubes. These calculations were carried out using the Gaussian 09 software package.