Pressure-induced phase transition of BeO

A constant pressure ab initio   technique is used to study the pressure-induced phase transition in BeO. A first order phase transition from the wurtzite structure to a rocksalt structure at 700.0 GPa is successfully observed in the constant pressure simulation. The wurtzite-to-rocksalt transformation is based on two fivefold coordinated intermediate states with space groups P63/mmcP63/mmc and Cmcm, similar to what has been observed or proposed in various wurtzite structured materials. This phase transition should occur around 70 GPa from the enthalpy calculations.