First-principles lattice dynamics, thermodynamics, and elasticity of Cr2O3

We present the calculation of the lattice dynamics of chromia (Cr2O3), a typical Mott–Hubbard insulator, employing the first-principles density functional theory plus U approach. We first report the phonon dispersions at the theoretical equilibrium volume. Then the phonon density-of-states is calculated as a function of volume. Finally, the atomic volume, heat capacity, linear thermal expansion coefficient, bulk modulus, Grüneisen constant, and elastic constants are calculated as functions of temperature. ► The lattice dynamics of Cr2O3 is studied by DFT+U approach. ► Phonon dispersions and phonon density-of-state of Cr2O3 are calculated. ► Thermodynamic properties as functions of temperature are computed. ► Thermal expansion coefficient as a function of temperature is computed. ► Elastic constants as functions of temperature are computed.