First-principles study of electronic structure and optical properties of heterodiamond BC2N

Heterodiamond BC2N, as a kind of superhard material expectable, is studied using the ab initio pseudopotential density functional method. All the calculations are performed after geometric optimization starting from an eight-atom zinc-blende structure unit cell. For all the structures possible, we calculate in detail the structural parameters, charge transfers, bond populations, band structures, density of states, and optical properties (dielectric function, refractive index, absorption coefficient, reflectivity, electron energy loss spectrum, and photoconductivity). In addition, the optical anisotropy of some structures is also discussed. Our calculated results show that all the structures are metastable and some of them tend to form graphitelike structures and exhibit semimetallic behavior leading to interesting optical properties.