Using the crystal parameters (Tables ), the electronic band structures and the density of states (DOS) were obtained using the all-electrons DFT-based augmented spherical method (ASW) and the GGA XC functional . The left panels of Fig. show the bands developing along the main directions of the primitive hexagonal Brillouin zone. Along the vertical direction y-axis, the energy zero is taken with respect to E V , i.e. the top of the valence band VB, which is separated from the conduction band CB by a large energy gap. As in diamond, C 8 has a band gap of E gap ~5 eV. In BN, a larger band gap E g ≈ 6 eV is observed due to the polar covalent character, but in BC 2 N the band gap E g ~5 eV becomes closer to C 8 , indicating that the polar covalent behavior of BN (cf. Fig. ) is less pronounced upon introduction of carbon into BN leading to the hexagonal BC 2 N.