Theoretical investigation on the cylinder-shaped N66 cage

► A large nitrogen-only cage with D3h symmetry is studied with high-level computations. ► Cylindrical shape is an important factor for the stability of nitrogen-only cage molecules. ► Pentagons on the side of the cylinder and triangles on the caps play important roles for the stability of the sylinder. ► Calculations show that the N66 cage is a novel nanomaterial (beeline nanotube).