Establishing baselines for generative discovery of inorganic crystals

TL;DR

This paper benchmarks traditional and generative AI methods for inorganic crystal discovery, showing that ion exchange favors stability while generative models excel at novel structures and property targeting, with filtering improving success rates.

Contribution

It introduces baseline methods and compares them with advanced generative models, providing a framework for evaluating and improving materials discovery techniques.

Findings

Ion exchange better at generating stable, known-like materials.

Generative models produce more novel structures and target properties effectively.

Filtering with pre-trained ML models significantly improves success rates.

Abstract

Generative artificial intelligence offers a promising avenue for materials discovery, yet its advantages over traditional methods remain unclear. In this work, we introduce and benchmark two baseline approaches - random enumeration of charge-balanced prototypes and data-driven ion exchange of known compounds - against four generative techniques based on diffusion models, variational autoencoders, and large language models. Our results show that established methods such as ion exchange are better at generating novel materials that are stable, although many of these closely resemble known compounds. In contrast, generative models excel at proposing novel structural frameworks and, when sufficient training data is available, can more effectively target properties such as electronic band gap and bulk modulus. To enhance the performance of both the baseline and generative approaches, we implement a post-generation screening step in which all proposed structures are passed through stability and property filters from pre-trained machine learning models including universal interatomic potentials. This low-cost filtering step leads to substantial improvement in the success rates of all methods, remains computationally efficient, and ultimately provides a practical pathway toward more effective generative strategies for materials discovery. By establishing baselines for comparison, this work highlights opportunities for continued advancement of generative models, especially for the targeted generation of novel materials that are thermodynamically stable.