First-Principle Study of Structural, Elastic Anisotropic, and Thermodynamic Properties of P4̅m2-BC7

The structural, elastic, anisotropy, and thermodynamic properties of R3-B2C were investigated using first-principles density functional calculations. The calculated equilibrium parameters are in good agreement with the available theoretical results. The elastic constants, elastic modulus, and elastic anisotropies of R3-B2C were also determined in the pressure range of 0–100 GPa. The calculated elastic modulus indicates that R3-B2C is a potential superhard material. The calculated elastic anisotropic factors suggest that R3-B2C is elastically anisotropic. A band structure study shows that R3-B2C is a direct semiconductor with band gap of 0.170 eV. Moreover, we predict the thermodynamic properties and obtain the relationships among the thermal expansion, temperature, and pressure, as well as the  