First-principles calculations on phase transition and elasticity of CdO under pressure

First-principles calculations of the crystal structures, and phase transition, and elastic properties of cadmium oxide (CdO) have been carried out with the plane-wave pseudopotential density functional theory method. The calculated values (for crystal structures) are in good agreement with experimental data as well as with some of the existing model calculations. The dependence of the elastic constants cijcij, the aggregate elastic modulus (BB, GG, EE), and the elastic anisotropy on pressure have been investigated. Moreover, the variation of the Poisson ratio, Debye temperature, and the compressional and shear elastic wave velocities with pressure PP up to 119 GPa at 0 K have been investigated for the first time. We also find that NaCl-type CdO should be unstable at pressures higher than 119.07 GPa.