Energetics and stability within the microscopic, empirical model for finite, open-ended, single-walled carbon nanotubes

We demonstrate that the total energy of finite, open-ended, single-walled carbon nanotubes is determined by a balance between the elastic energy due to the curvature of a tube and the chemical energy due to the dangling bonds at the open ends of a tube. The differences in total energy and radius between the most energetically stable zig-zag and armchair tubes, increases with increasing number of atoms in the tubes