3 Thermodynamically stable compounds in the Mg-O system

We have performed structure searches with up to 20 atoms in the unit cell at pressures in the range of 0-850 GPa for the Mg-O system. These searches yielded MgO as a stable oxide, but additionally two new compounds were predicted to be stable in the regions of high and low oxygen chemical potential, respectively. To confirm this and to obtain the most accurate results, we then focused search on two separate regions of chemical space; Mg-MgO and MgO-O, respectively. Since the structures in the two regions exhibit different properties, we report them separately.