Efficient small-cell sampling for machine-learning potentials of multi-principal element alloys
Yan Liu, Jiantao Wang, Hongkun Deng, Yan Sun, Xing-Qiu Chen, Peitao Liu
TL;DR
This work tackles the challenge of modeling multi-principal element alloys (MPEAs) with machine-learning potentials by introducing an efficient one-shot small-cell sampling (SCS) protocol. By enumerating symmetry-inequivalent unary and binary configurations within 4-, 8-, and 12-atom cells and filtering near-binary convex-h hulls from the Materials Project, the authors generate diverse training datasets augmented with targeted perturbations, avoiding iterative active learning and large-cell DFT. They train two ML potentials (MTP and MACE) and validate the approach across TiZrHfCuNi, TiZrVMo, CoCrFeMnNi, and AlTiZrNbHfTa, demonstrating accurate structural, thermodynamic, and ordering predictions, including phase transformations and SRO evolutions. The results establish a scalable, low-cost pathway toward universal MPEA MLPs and offer insight into how small-cell data can effectively represent complex multicomponent energy landscapes for accelerated materials discovery.
Abstract
Multi-principal element alloys (MPEAs) exhibit exceptional properties but face significant challenges in developing accurate machine-learning potentials (MLPs) due to their vast compositional and configurational complexity. Here, we introduce an efficient small-cell sampling (SCS) method, which allows for generating diverse and representative training datasets for MPEAs using only small-cell structures with just one and two elements, thereby bypassing the computational overhead of iterative active learning cycles and large-cell density functional theory calculations. The efficacy of the method is carefully validated through principal component analysis, extrapolation grades evaluation, and root-mean-square errors and physical properties assessment on the TiZrHfCuNi system. Further demonstrations on TiZrVMo, CoCrFeMnNi, and AlTiZrNbHfTa systems accurately reproduce complex phenomena including phase transitions, chemical orderings, and thermodynamic properties. This work establishes an efficient one-shot protocol for constructing high-quality training datasets across multiple elements, laying a solid foundation for developing universal MLPs for MPEAs.
