Molecular packing analysis of benzene crystals. Part 2. Prediction of experimental crystal structure polymorphs at low and high pressure

Abstract

Abstract Benzene crystal structures were obtained by pseudoannealing initial structures sampled from a trajectory of constant moles, volume, and temperature molecular dynamics (NVT MD). The crystal structure of the observed low pressure phase I was reproduced as the most stable state and other crystal structures, which included high pressure phase III, were obtained as metastable states at zero pressure. The pressure dependence of enthalpy was analyzed for these crystal structures, and the relative stability among these crystal structures is discussed, at pressures up to 4 GPa. The observed low pressure phase I was the most stable state up to 1.4 GPa and the high pressure phase III was the most stable state above 1.4 GPa. The reported high pressure phase II was not obtained in this work at any pressure up to 4 GPa.