The band structure features are reflected in the site-projected electronic densities of states, DOS, shown in Fig. with energy along the horizontal axis and DOS in 1/eV units along the vertical axis. qtz C 6 , expressed as C1 3 C2 3 , is characterized by identical DOS for both sites and a continuous VB extending over ~27 eV, indicating the purely covalent nature of the carbon allotrope. The sharp DOS peak at 1 eV below EV belongs to the carbon p-states, which are more localized than the s-states smeared in the lower part of the VB. The (empty) CB also shows structured p-DOS. Turning to the binary compounds, the VB is now divided into two parts corresponding to s-states up to -15 eV in qtz BN (-9 eV in qtz SiC), followed by a broad block up to EV. The band gap in qtz BN is the largest, ~5 eV, which is close to c-BN, while qtz SiC has the smallest band gap of about 1.5 eV.