Theoretical study on structural and electronic properties of solid anthracene under high pressure by density functional theory

Based on the density functional theory, a theoretical determination method is applied to investigate structural and electronic properties of anthracene up to 27 GPa. The lattice parameters a, b, c, decrease by 1.53 (-18.2%), 0.76 (-12.8%), and 0.93 (-8.4%), respectively, while the monoclinic angle β increased by 4.65° in this pressure region. At the highest pressure of 27 GPa the unit cell volume is decreased by 58.9%. These findings are shown to be in agreement with experimental results and hint towards the evolution of intermolecular interaction with pressure. The calculated electronic band splitting and the band gap reduce smoothly to some extent with the pressure increasing. Moreover, a pressure-induced decrease of the band gap is observed.