  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.
