Pressure-induced phase transition of AgClO4: A first-principles study

The high-pressure structural stability of AgClO4 is investigated by using first-principles calculations based on density functional theory (DFT). Our results demonstrate that the pressure-induced phase transformation of AgClO4 is the tetragonal structure ( I 4 ¯ 2 m ) to the orthorhombic barite-type structure (Pnma) at 3.5 GPa, and then to monoclinic structure ( P 2 1 / m ) at 54 GPa. The calculated electronic band structures indicate that tetragonal AgClO4 has indirect gap of 2.67 eV, barite-type and monoclinic structures at transition pressure have direct gap of 3.11 eV and 4.05 eV, respectively. The electron density difference indicates that there exist ionic interaction between these atoms. Based on the value of B/G ratio, tetragonal structure of AgClO4 is predicted to be ductile.