First-principles determination of multicomponent hydride phase diagrams: application to the Li-Mg-N-H system

Complex solid-state hydrides can store hydrogen at very high volumetric and gravimetric densities. We present a theoretical framework, which automatically determines phase diagrams and thermodynamically favored hydrogen storage reactions in complex multicomponent systems, such as Li-Mg-N-H (see figure). This method can be used to efficiently scan the phase space and pinpoint those compositions, which have the greatest potential for thermodynamically reversible HZ storage.