Fig. shows the electronic band structures for three new C 6 allotropes obtained using the allelectrons DFT-based augmented spherical method (ASW) . The energy level along the vertical line is with respect to the top of the valence band (VB), E V . The VB is largely separated from the empty conduction band CB by a large band gap amounting to ~5 eV. Such insulating electronic character resembles diamond. A few features relevant to the nature of the band gap can be observed such as the indirect in orthorhombic and hexagonal (trigonal) C 6 , like in diamond but identified as indirect between Γ VB and Γ CB in tetragonal C 6 allotrope.