Calculations were conducted using GGA+PBE with a unit cell of 2 formula units (2 Zr and 4 O) using CASTEP
code in the Material Studio modeling package (MS). The convergence criteria of the free energy with the k-points
sampling and the cut-off energy for approximation have been cautiously examined. In order to make sure that the
calculation was converged, the total energy difference was set below 10-5 eV. The Monkhorst-Pack defined 3