Investigation of structural, elastic, electronic, optical and vibrational properties of silver chromate spinels: Normal (CrAg2O4) and inverse (Ag2CrO4)

Structural and elastic properties of silver chromate in normal (CrAg2O4) and inverse (Ag2CrO4) spinel structure have been studied using density functional theory (DFT) together with Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional implemented in VASP package. It is observed that studied compound satisfy the well-known requirements of mechanical stability for cubic crystals. So we can infer that studied compound is stable both in normal (CrAg2O4) and inverse (Ag2CrO4) spinel structure. Electronic, optical and vibrational properties of Ag2CrO4 at 0 and 11 GPa have also been studied. Zone-centre phonon frequencies and the phonon dispersion relations along high symmetry directions of the silver chromate have been calculated using phonon software with the forces calculated with VASP. Our calculated lattice constant values, Raman spectrum modes and fundamental bandgap values are in good agreement with recent studies which can motivate further experimental and theoretical attention.