Evaluating Species Stability with First Principles Calculations

Novel multicomponent materials such as BiCuOS and BiCuOSe are used in a wide variety of applications like structural materials, semiconductors, and catalysis; however, the complex chemistry of having multiple anions makes reliable synthesis of these products challenging. Here we describe an ab-initio approach to evaluate the thermodynamic stabilities of multicomponent solids in aqueous environments with variable environmental conditions. The approach allows us to generate electrochemical Pourbaix diagrams that can be used to guide hydrothermal synthesis of these complex phases. Furthermore, we utilize a revised Helgeson-Kirkham-Flowers model to incorporate nonstandard state conditions for aqueous ions as functions of temperature and pressure. Our work identifies the main factors needed for the informed synthesis of new complex transition metal compounds and routes to deliver long-term stability of copper-based alloys.