Figure 2 - Electronic structure of polymeric melon.

a, Density-functional-theory band structure for polymeric melon calculated along the chain (–X direction) and perpendicular to the chain (Y– direction). The position of the reduction level for H⁺ to H₂ is indicated by the dashed blue line and the oxidation potential of H₂O to O₂ is indicated by the red dashed line just above the valence band. b, The Kohn–Sham orbitals for the valence band of polymeric melon. c, The corresponding conduction band. The carbon atoms are grey, nitrogen atoms are blue and the hydrogen atoms are white. The isodensity surfaces are drawn for a charge density of 0.01q_e Å^-3.