High-pressure phase transitions in diamond and zinc-blende semiconductors

With the advent of accurate total-energy methods for solids, it has become feasible to determine the relative structural energies of simple solids as a function of pressure. We use such a method coupled with an empirical ionicity scale to predict phase transitions as a function of pressure for all diamond and zinc-blende semiconductors of the form AN{B}^{8{{-}}N}$ where A and B are simple metals or metalloids and N is the number of valence electrons for species A. We find satisfactory agreement between the predicted transition from zinc-blende structure to rocksalt or {β}-Sn structures and high-pressure experiments. In addition, we find that changes in ionicity to a large extent control whether the diamond or zinc-blende structure will transform preferentially to rocksalt or to {β}-Sn; whereas, for changes in the equilibrium crystal volume, we find the magnitude of the transition pressure changes, but not the structural preference.