Structural and electronic distortions in hydrogenated single-walled zigzag carbon nanotubes

In this paper, we have investigated hydrogenated single-wall zigzag carbon nanotubes from (7,0) to (11,0) by using pseudopotential-based density functional theory. We found that the structure deformation of configuration follows the way preserving high symmetry as possible. One typical process that two dimer chains along the axis direction separate on CNT is presented. The configuration is more stable as the inter-dimer distance increases. Meanwhile, the carbon bond angles decrease differently due to the hydrogen adsorption site or not, but the C-C band length is insensitive to the dimer chains separation process. The electronic distortions are demonstrated that all configurations show metal behavior for zero interval and the gaps undergo increment with the dimer chains separation increment regardless of tubes chirality, which is related to the hybridization resulting in changing the free electron state and the Fermi level. Furthermore, there is a localized electron distribution behavior difference at hydrogenated carbon site or not.