Effects of Lagrangian multipliers on SWCNT in real space

Electronic properties, band-width, band gap, and van Hove singularities of (3,0), (4,0), and (9,0) zigzag nanotubes are investigated comparatively in the Harigaya model and a toy model, including the contributions of bonds of different types to the SSH Hamiltonian differently. Optical transition frequencies are calculated. In this way, an experimental correlation between the two models is achieved. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006