In order to determine the minimum energy adsorption structure for CS2 on the surface of the tube, a number of distinct starting structures have been used for optimization including both the carbon and sulfur atoms of CS2 being close to CAC and CAB bonds, and sulfur atom close to the B atom, two sulfur atoms locating on the top of two B or two C atoms and one of the sulfur atoms being above the center of hexagonal rings. After careful structural optimizations,re-orientation of the molecule has been predicted in some cases, and finally four stable CS2/BC3NT complexes were obtained (Figs. 2 and 3)