Chapter 4 - Nested Carbon Nanostructures

Abstract

In general, particles tend to organise themselves into their most stable structures, which are the minimum energy configurations and this is also true at the atomic level. When two atoms are far apart an attractive force pulls them closer to each other, but if they are too close a repulsive force pushes them away. There exists a certain separation distance where the two atoms are most likely to be, namely where the interaction energy between them is at a minimum. This distance is termed the equilibrium distance. Ideally, atoms prefer to be apart by a distance equivalent to their equilibrium distance, as do molecules and other nanostructures. This chapter focuses on the determination of stable equilibrium configurations for nested carbon nanostructures. A nested structure refers to a structure that comprises both inner and outer components. We begin by examining the simple case where the inner structure is simply a single atom. Then we extend the analysis to more complicated structures, including fullerene@fullerene (carbon onion), fullerene@nanotube, nanotube@nanotube, and carbon onion@nanotube. We note that the convention X@Y denotes a nested structure for which molecule X is nested inside molecule Y. In the final parts of this chapter we look at the interaction of many body systems. For example, the case of a nested atom or molecule either inside a uniform concentric ring or a nanotube bundle.