Fig. shows the electronic band structure and the site projected density of states (DOS) of tet-C 6 obtained using the all-electrons DFT-based augmented spherical method (ASW) using GGA exchange correlation functional . In Fig. the energy level along the vertical line is with respect to the Fermi level (E F ) crossed by bands with subsequent metallic behavior. The DOS shown beside the band structure (Fig. ) provide further interpretation for the electronic structure with the zero energy along the x-axis at E F . The projected DOS along C1 (tetrahedral) and C2 (trigonal) sites show large similarities in the energy range {-20; -5 eV} ensuring for the chemical bonding between the two sites, but large differences appear above -5 eV and above E F within the (empty) conduction band. The prevailing C2-DOS at E F and the vanishingly small C1 magnitude of C1 DOS clearly show that the conductivity is selectively caused by trigonal carbon as discussed in the charge density subsection. Further support is also found from the weighted bands in Fig. where the bold bands relative to C1 are found deeper in energy whereas C2 bands are found responsible of the states crossing E F , thus responsible of the metallic character and resulting from the π-electrons having more itinerant behavior than the less extended  electrons.