Modeling chemisorption of carbon dimer at (8, 0) nanotube

The electron structures of two forms of the grafted carbon dimer for the (8, 0) zigzag nanotube were calculated by the semi-empirical quantum- chemistry method applied to the supercell model. If the dimer adsorbs above the center of the tube's hexagon (h-grafting), it performs the topochemical transformation of the tube, according to the Stone–Wales scheme of inverse kind. B-grafting is a chemisorption above tube's bond, it is energetically lower, than h-grafting. Atomic structure of b-grafting is a splitted di-interstitial. Measuring the electronic density of states in the upper valence bandhas been shown to make it possible to distinguish between pure and grafted nanotubes, as well as between b- and h-graftings.