Phase transition of GeO2 crystal at high pressure: An ab initio molecular dynamics study

The phase transition of GeO 2 structure was studied under constant pressure by using ab initio calculation and the generalized gradient approximation (GGA). A structural phase transition was observed at 30 GPa for the first time under the constant hydrostatic pressure, and P4 2 /mnm structure was transformated into a CaCl 2 (Pnnm) structure. This phase transition was also investigated using total energy, enthalpy, and the phase shift calculations. It was determined that the obtained transformation parameters and bulk modulus properties were compatible with the previous experimental and theoretical first principle calculations.