First-principles study of electronic and optical properties of cubic AgTaO₃ structure in paraelectric phase at different pressures

ABSTRACT

In the present article, a theoretical study of structural properties, energy band structure, total (TDOS) and partial (PDOS) density of states, real and imaginary parts of photon frequency dependent complex dielectric function of cubic AgTaO₃ in paraelectric phase was presented by ab-initio calculations using DFT-LDA in the ABINIT code. The obtained energy band structure under various pressures shows that AgTaO₃ has an indirect band gap at the Γ and M points in the first Brillouin zone which increases by increasing pressure. Calculated results for energy band gap and optical properties under pressure are given and these results were compared with the experimental results and previous calculations.

KEYWORS:

• DFT-LDA
• structural properties
• electronic structure
• dielectric function
• ABINIT