Materials Discovery Using Uncertainty-Aware Constrained Bayesian Optimization with Representation Learning of High-Dimensional Inputs

High-dimensional structure and composition spaces pose a fundamental challenge in materials discovery due to the lack of efficient approaches for navigating the vast and complex design space. Although machine learning (ML) has aided materials discovery, most existing ML models lack the ability to quantify epistemic uncertainty arising from limited data. Developing this capability is particularly challenging for tasks involving high-dimensional design representations, such as atomic structures. In this study, building on the Bayesian optimization (BO) framework, we propose an uncertainty-aware atomistic machine learning model, uncertainty-aware PointNet, which enables automated representation learning directly from high-dimensional design inputs, such as atomic structures, and achieves principled uncertainty quantification through the use of spectral-normalized neural Gaussian process. By utilizing a constrained expected improvement acquisition function, our BO framework simultaneously considers multiple design criteria. We demonstrate the effectiveness of our approach in two materials discovery case studies: (1) identifying catalysts for the carbon dioxide reduction reaction and (2) designing transparent conducting materials. The results show that our approach achieves high prediction accuracy, facilitates interpretable feature extraction, and enables multicriteria material design using constrained BO, leading to a significant reduction of computing power and time (a 10 & times; reduction in required simulation calculations). Beyond the demonstration examples, the developed method can accelerate materials discovery for various other applications with high-dimensional design inputs and expensive physics-based simulations.