Elastic and electronic properties of cubic cerium oxide under pressure via first principles

The elastic and electronic properties of cubic structure CeO2 under pressure are investigated in the frame of density functional theory (DFT). By using the local-density approximation (LDA) plus U (LDA+U) method with U = 6 eV, the calculated lattice parameters, bulk modulus and elastic properties of the cubic CeO2 at 0 GPa and 0 K are in good agreement with the available experimental data. The pressure dependences of lattice parameters, bulk and shear modulus, Debye temperature, Young's moduli, Poisson's ratio and the compressional and shear wave velocities of the cubic CeO2 are obtained successfully. In addition, the total density of states (TDOS) and the band gaps of the cubic CeO2 under pressures are also investigated. By comparing the results of LDA and LDA+U, both the conventional LDA and the LDA+U methods can be used to describe the structure of the cubic CeO2 due to the electronic localization of 4f-electron in Ce which is not so strong. However, the LDA+U approach can obtain a proper shape of the density of electronic states that agrees well with the measured values.