B–C–N Compounds with Mixed Hybridization of sp²-Like and sp³-Like Bonds

We perform first-principles calculations of the structural and electronic properties of hypothetical bc6-BC₄N and N-substituted bc6-BC₄N, which are derived from a body−center-cubic carbon structure. Our calculations show that the former is a semiconductor with an indirect band gap of 0.91 eV and the latter is metallic. The calculated bond length, bond population, and charge density of N-substituted bc6-BC₄N indicate that one C−N bond has been broken after N-substitution, which means that the structure contains a mixed hybridization of sp²-like and sp³-like bonds. At the pressure above 100 GPa, the structure changes to a pure sp³-like hybridization.