¹³C NMR chemical shift of single-wall carbon nanotubes

A systematic study of the ¹³C NMR chemical shifts of single-walled carbon nanotubes (SWNT) was presented. Results show that the Knight shift and the intra-atomic part of the orbital contribution can be removed without losing the physical relevance of the computations. The ring currents' contribution to the NMR shift of perfect and isolcated SWNT shows a 11 ppm splitting between the isotropic lines of semiconducting and metallic nanotubes. This distinct response could be used to characterize the electronic structure of a bulk nanotube sample.