Increased metallicity of Carbon nanotubes because of incorporation of   extended Stone-Wales' defects: an ab-initio real space approach
  We propose an ab-initio combination of the Linear Muffin-Tin Orbital and the Recursion Methods to study the effect of extended Stone-Wales defects in single layer Carbon nanotubes. We have successfully applied this to zigzag and armchair tubes. The methodology involves no intrinsic mean-field like assumptions or external parameter fitting. As defects proliferate, the low density of states near the Fermi levels of the pristine tubes is filled with defect states. The increase of DOS at the Fermi level leads to enhanced conduction, which indicates enhanced metallicity due to SW defects in the nanotubes. 
Sujoy Datta, Banasree Sadhukhan, Chhanda Basu Chaudhuri, Srabani   Chakraborty, Abhijit Mookerjee
cond-mat.mes-hall