KGRxn-LLM: Knowledge Graph Enhanced Large Language Models for Molecular Reaction Reasoning

Weichen Liu, Qiyao Xue, Yuyang Wu, Olexandr Isayev, Natasa Miskov-Zivanov


Abstract
Large language models (LLMs) demonstrate strong general language capabilities but remain limited in chemical reasoning, particularly for tasks requiring structured, mechanistic understanding of molecular reactions. We present Knowledge Graph Reaction LLM (KGRxn-LLM), a framework that augments LLMs with a hierarchical chemical knowledge graph (KG) to ground reasoning in molecular transformations and reaction patterns. Existing benchmarks primarily emphasize reaction or molecular fact recall, providing limited assessment of reaction-level mechanistic reasoning. To address this gap, we introduce KGRxn-Bench, a benchmark of 1,200 questions designed to evaluate LLMs on reaction-centric reasoning tasks, including functional group identification, reaction type classification, and product and reagent prediction. Experimental results show that our approach of grounding LLMs in structured KG substantially improves performance across multiple tasks and model backbones, outperforming domain-specific fine-tuned models on KG-covered splits and most hold-out splits.
Anthology ID:
2026.bionlp-1.22
Volume:
BioNLP 2026
Month:
July
Year:
2026
Address:
San Diego, California
Editors:
Dina Demner-Fushman, Sophia Ananiadou, Kirk Roberts, Junichi Tsujii
Venues:
BioNLP | WS
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Publisher:
Association for Computational Linguistics
Note:
Pages:
268–281
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-1.22/
DOI:
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Cite (ACL):
Weichen Liu, Qiyao Xue, Yuyang Wu, Olexandr Isayev, and Natasa Miskov-Zivanov. 2026. KGRxn-LLM: Knowledge Graph Enhanced Large Language Models for Molecular Reaction Reasoning. In BioNLP 2026, pages 268–281, San Diego, California. Association for Computational Linguistics.
Cite (Informal):
KGRxn-LLM: Knowledge Graph Enhanced Large Language Models for Molecular Reaction Reasoning (Liu et al., BioNLP 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-1.22.pdf