density functional theory studies of defects in the (5,5) silicon nanotube

we have performed density functional theory (dft) calculations to investigate the properties of defect in arepresentative armchair model of silicon nanotubes (sints). to this aim, the structures of pristine and defective(5,5) sints have been optimized and the properties such as bond lengths, total energies, binding energies,.formation energies, gap energies, and dipole moments have been evaluated for the optimized structures. theresults indicate that the evaluated properties could yield the effects of the defect on the properties of pristinesint.