Structural, elastic, and electronic properties of MgB 2 C 2 under pressure from first‐principles calculations

First‐principles calculations using the projected augmented plane wave method have been performed to investigate the structural, elastic, and electronic properties of MgB 2 C 2 under different pressures. The results indicate that the ternary compound MgB 2 C 2 remains mechanically stable under pressure ranging from 0 to 50 GPa. Elastic analysis is performed, and it is found that MgB 2 C 2 always shows obvious intrinsic brittleness under pressure, although there is an increasing trend of ductility, both from B H / G H and ν H , with increasing pressure. (100), (010), and ( 1 1 ¯ 0 ) planes show strong anisotropy, and the degree of anisotropy decreases with increasing pressure; in the meantime, it is interesting to find that the degree of anisotropy is reduced in the following order of planes1 1 ¯ 0 → 100 → 010 under the same pressure.