Structures and electronic properties of peanut-shaped dimers and carbon nanotubes.

The structures and electronic properties of peanut-shaped dimers and carbon nanotubes constructed from C60 molecules are investigated using ab initio self-consistent field molecular and crystal orbital methods based on the density-functional theory. The calculations show that the formation of peanut-shaped structures without octagonal carbon rings is energetically favorable. The obtained band structures indicate that the peanut-shaped nanotube can be a semiconductor or a metal.