Commensurability effect on the electronic structure of carbon nanostructures: Impact on supercell calculations in nanotubes. (9th March 2017)

• Record Type: Journal Article
• Authors: Ferreira, M. S.; Rocha, C. G.; Lawlor, J. A.; Venezuela, P.; Amorim, R. G.; Rocha, A. R.
• Is Part Of: Europhysics letters. Volume 117:Number 2(2017:Jan.)
• Publication Date: 2017-03-09
• Subjects: 71.15.-m -- 73.63.Fg -- 73.22.Pr; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/117/27005
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: Friedel oscillations are ubiquitous features seen in all impurity-doped metallic structures but in the case of graphene-like materials they are not so evident because the relevant wavelengths are perfectly commensurate with the lattice parameter. Here we demonstrate that this commensurability effect leads to a slow convergence of supercell-based total energy calculations in impurity-doped carbon nanotubes. We derive a mathematically transparent expression for the formation energy and identify a very distinctive dependence on the size of the supercell unit. We make use of this dependence through a simple extrapolation scheme to obtain density functional theory results with accuracy levels that would otherwise require enormously large unit cells.