Density-functional theory investigation of electronic structure, elastic properties, optical properties, and lattice dynamics of Ba₂ZnWO₆

The electronic structures, optical dielectric functions, elastic properties, and lattice dynamics of Ba₂ZnWO₆ have been investigated by using the generalized gradient approximation. The density of states and distributions of charge density show that O and Ba tend toward ionic bond, but O and W or Zn display the covalent bond character. The calculated energy band structure shows that Ba₂ZnWO₆ is a wide indirect band gap semiconductor. The static value 2.28 of the refractive index is attained. The analysis of the elastic properties of Ba₂ZnWO₆ indicates a rather weak elastic anisotropy. The phonon dispersion is calculated, suggesting no structure instability, which is agreement with the recent low temperature neutron diffraction experiments. The mensurability C_v (phonon heat capacity) as the function of the temperature is also calculated to judge our results for future experiment.