A first-principle study of electronic structure and mechanical property of graphyne nanotubes

Based on the first principle calculations, the geometry structure, electronic structure and Young's modulus of single-wall graphyne nanotubes (GNTs) are studied. It is found that GNTs are semiconductors with the direct band gap in range of 0.40 eV∼1.3 eV. Due to curvature effects, the band gap decreases with the increase of GNTs, diameter. The calculated Young's modulus of GNTs is between 0.44 and 0.50 Tpa. For zigzag GNTs, the Young's modulus decreases with the increase of tube diameter, while for armchair GNTs, it increases with the increases of tube diameter. (authors)