Structural and elastic properties of MgS via first-principle calculations

The structural B1–B2 (B1 is the NaCl phase and B2 is the CsCl phase) phase transition of MgS and the elastic properties of the B1 and B2 phases of MgS are investigated by ab initio plane-wave pseudopotential density functional theory method. The dependences of the elastic constants cij, the aggregate elastic modulus BS, G, and the Debye temperature ΘD on pressure are successfully discussed. From the usual condition of equal enthalpies, we find that the structure B1–B2 phase transition of MgS occurs at 255.5 GPa. Moreover, the dependences of the aggregate elastic modulus and the Debye temperature on the pressure P have been investigated for the first time.