Figure 1

Top (upper) and side (lower) views of (a) a (2 × 2) reconstructed g-C4N3 supercell. The blue and grey balls represent N and C atoms, respectively and the unit cell of g-C4N3 is indicated by red dot lines. C1 and C2 denote different C atoms in g-C4N3 unit cell. The calculated band structures of (b) a (2 × 2) reconstructed g-C4N3. The blue dashed line denotes the Fermi level. The red and black lines in (b) denote the spin-up and spin-down states, respectively.