Structural, electronic, bonding and thermo-elastic properties of orthorhombic and cubic CeO2 compound

• First systematic research has been performed using the first principles calculations.
• Investigate the electro-structural and thermal properties within FP-LAPW framework.
• Study the dynamic and elastic properties of CeO2 compound.
• Elaborate the chemical bonding of CeO2 compound.

The full potential linearized augmented plane plus local orbitals method within the framework of density functional theory is employed to investigate the structural, elastic, thermal, electronic properties and chemical bonding of CeO2 cubic and orthorhombic phases. The calculated structural parameters are found in good agreement with the available results. The compound is elastically stable in both phases. It is seen that the unit cell volume increases while the bulk modulus decreases as the temperature increases. The compound has wide and direct bandgap in orthorhombic phase while is has indirect band gap in the cubic phase. Furthermore, the thermodynamical properties of CeO2 are predicted for the first time through the quasi-harmonic Debye model, in which the lattice vibrations are taken into account. The variation of relative change in volume, bulk modulus, heat capacities and thermal expansion coefficient with temperature and pressure are successfully achieved.