Simulating Pressure-Driven Solid--Solid Phase Transformations Across Crystal Structure Types

Materials' properties can vary widely based on the pressure at which they are formed and the crystal structure that they adopt---an example being the graphite and diamond allotropes of carbon. Many materials undergo structural transitions if they are put in a pressurized environment. Here, we investigate the high-pressure behavior of sixteen known, self-assembled structures under isotropic compression. We model these systems with molecular dynamics simulations of particles that interact via simple pair potentials. Particles, which spontaneously self-assemble into these different crystal structures, are initialized and then pressurized through a successively decreasing simulation box size. We observe pressure-driven solid--solid phase transitions across structure types, as well as a variety of other transformation behaviors as a function of pressure. We compare our findings with the pressure-dependent structural behavior that is known from atomic systems. Our work expands current knowledge on relationships between structure and pressure, and paves the road toward switchable materials.