Computational Analysis of the Energetic Stability of High-Entropy Structures of a Prototypical Lanthanide-Based Metal–Organic Framework

High-entropy materials are characterized by their complex
compositions,
typically comprising five or more elements in near-equiatomic proportions.
Applying this concept to metal ions in metal–organic frameworks
(MOFs) has paved the way for exploring a new class of high-entropy
MOFs. While the compositional strategy of high-entropy materials leverages
configurational entropy to aid thermodynamic stability, it also poses
significant analytical challenges due to the vast compositional landscape
and diverse phases that these materials can adopt. We present a computational
study of several complexities associated with selecting potential
high-entropy versions of a prototype lanthanide-based MOF. We compute
the energetics of metal mixing of these heterometallic MOFs using
density functional theory (DFT) and machine learning interatomic potential
(MLIP) methods. The use of MLIP methods allows a systematic exploration
of the convex hull of thermodynamically stable MOF structures containing
up to 5 distinct metals.