Atomistic simulations of the pressure-induced phase transitions in BaF2 crystals

The pressure-induced sequence of phase transitions of the BaF2 fluorite was studied within the shell-model approach. This fluorite crystal presents two pressure-induced phase transitions at approximately 3 and 15 GPa. The interatomic potentials were calculated by using relevant physical properties measured at ambient conditions. These potentials were used to minimize the lattice enthalpy at high hydrostatic pressures. By comparing the enthalpies and lattice parameters of the three possible structures, it was possible to describe the complete phase transition sequence of the material. The model reliability is confirmed by a comparison with experimental results reported at ambient conditions, which are in good agreement with the model predictions.