Metastable polymeric nitrogen nanotube from a zigzag sheet phase and first-principles calculations

A metastable zigzag sheet phase of polymeric nitrogen has been theoretically predicted in phase transformations from the theoretically predicted structures of a denser nitrogen molecular zeta phase. Built from this sheet structure, a polymeric nitrogen nanotube is postulated to comprise 18 zigzag single-bonded N(6) motifs and computationally modeled using first-principles density-functional theory. The metastability of the nitrogen tube was demonstrated with structural optimization calculations, phonon dispersion calculations, and finite-temperature first-principles molecular-dynamics simulations. Band-structure calculations show that this metastable polymeric nitrogen nanotube is an insulator with a band gap of about 3.0 eV.