A reasonable criterion of nitrogen-doped single-walled carbon nanotubes with pyridine-like configurations

► Bond curvature as a universal criterion is applied to nitrogen-doped SWCNTs. ► Products with pyridine-like and perfect sp2 hexagonal structures are obtained. ► Forming mechanism of products with pyridine-like structure is studied. ► Electronic structures of perfect SWCNTs affect nitrogen-dopings.