Atomic cluster expansion for the aluminum-magnesium-hydrogen system

Aluminum-magnesium alloys are widely used in engineering, but their susceptibility to hydrogen embrittlement and intergranular corrosion limits their applications. Understanding these phenomena requires accurate atomistic modeling of the ternary Al-Mg-H system, which has been hindered by the lack of reliable interatomic potentials. This work presents a ternary atomic cluster expansion (ACE) potential for Al-Mg-H, trained on an extensive density functional theory dataset using active learning. The ACE potential accurately reproduces a wide range of properties, including defect energetics, phase stability, and diffusion coefficients. Thanks to its outstanding computational efficiency, ACE can be employed in large-scale atomistic simulations that help elucidate the nanoscale mechanisms of hydrogen-related degradation in Al-Mg alloys.