Elastic and electronic properties of Ce2O3 from first principles

Highlights: ► By the LDA + U method with U = 6 eV, the lattice constants, insulating gap, and bulk modulus of Ce2O3 obtained agree well with experimental and other theoretical data. ► Ce2O3 is quite sensitive to the change of U. ► The elastic constants, the anisotropies, the compressional and shear wave velocities, Young's modulus, Poisson's ratio, as well as the Debye temperature at U = 0 and 6 eV are obtained for the first time. - Abstract: Elastic and electronic properties of Ce2O3 have been investigated by performing calculations using the local-density approximation plus U (LDA + U) scheme in the frame of density functional theory (DFT). The strong on-site Coulomb repulsion of the localized Ce 4f electrons is amended by the LDA + U formalism, showing that Ce2O3 is quite sensitive to the change of U; the optimized choice of U is 6 eV. The calculated lattice constants, insulating gap, and bulk modulus agree well with the available experimental and other theoretical data. Moreover, the anisotropies, the compressional and shear wave velocities, Young's modulus, Poisson's ratio, as well as the Debye temperature have been calculated for U = 0, 2, 4 and 6 eV. It has been found that the elastic constants, bulk modulus, shear modulus, acoustic velocities, and Debye temperature of Ce2O3 are consistently decreasing upon increasing the U value.