Enthalpy landscapes of the earth alkaline metal oxides

Recent developments in the field of solid state synthesis have given us access to synthesis conditions that range from effective negative pressures of about -1 GPa to high positive values exceeding 10 or even 100 GPa. Thus, it becomes necessary to explore not only the landscape of potential energy, but also the enthalpy landscapes for a wide range of pressures when attempting to predict possible crystalline modifications in a chemical system. In this work, we present the enthalpy landscapes for the earth alkaline oxides. The results are compared with experimental and theoretical studies, and we predict that it should be possible to synthesize at least some of these compounds in the so-called 5-5 modification.