Understanding Oxide Surface Stability: Theoretical Insights From Silver Chromate

ABSTRACT Understanding the thermodynamic stability of surfaces under realistic environmental conditions is a central challenge in predicting materials behavior from first principles. Here we employ a first‐principles atomistic thermodynamics framework based on density functional theory (DFT) to systematically assess the relative stability of several surface orientations and terminations of silver chromate (). The surface Gibbs free energies were computed as functions of oxygen and silver chemical potentials, enabling the construction of a comprehensive surface phase diagram. This methodology captures the interplay between atomic‐scale structural motifs and the external thermodynamic environment, providing a robust route to predict surface stability beyond vacuum conditions. Silver chromate serves as a model system to illustrate the method, revealing that the coordination of surface chromium–oxygen clusters governs the relative stability of competing terminations. The approach further allows the prediction of morphology evolution via Wulff constructions, establishing a consistent theoretical framework for connecting first‐principles energetics to equilibrium crystal shapes.