Exascale Multi-Task Graph Foundation Models for Imbalanced, Multi-Fidelity Atomistic Data. - Massimiliano Lupo Pasini; Jong Youl Choi; Kshitij Mehta; Richard Messerly; Rylie Weaver; Linda Ungerboeck; Isaac Lyngaas; Benajmin Stump; Ashwin M. Aji; Karl W. Schulz; Jorda Polo (CoRR, 2026)