First principles study of 2-(acetoxy group)benzoic acid under different extremely high-pressure environments

Abstract

Based on Density Functional Theory (DFT), a first-principles study was conducted on the crystal structure, electronic structure, and optical properties of the organic material 2-(acetoxy group) benzoic acid crystal (C9H8O4) under extremely high pressure ranging from 0 to 300 GPa. The structure study revealed the significant bonding and bond breaking phenomena at pressures of 80 GPa and 270 GPa, respectively, indicating that it may induced the lattice phase transitions. The energy band analysis demonstrated that the crystal underwent a transition from a direct bandgap semiconductor at 0 GPa to an indirect bandgap semiconductor at 80 GPa, and then at 270 GPa, the crystal exhibited a metallic phase with a bandgap of 0. The density of states (DOS) provided evidence that this crystal undergo intricate phase transitions under extremely high pressure. The optical properties were further compared and analyzed. It was observed that the peak of optical absorption shifted towards higher energy regions, while the peak of photoconductivity and Loss function shifted towards the blue shift. These findings indicate that extremely high pressures can effectively modulate the structure and properties of C9H8O4 material. This research offers valuable insights for further exploration of the properties of C9H8O4 materials and their potential applications in organic optoelectronic devices.