Evaluating Multi-Hop Reasoning in Large Language Models: A Chemistry-Centric Benchmark
Mohammad Khodadad, Ali Shiraee Kasmaee, Mahdi Astaraki, Nicholas Sherck, Hamidreza Mahyar, Soheila Samiee
Abstract
We introduce ChemComp, the first chemistry-focused benchmark for evaluating compositional multi-hop reasoning in large language models (LLMs). Our automated pipeline constructs benchmarks from proprietary or public data by integrating generative reasoning models, chemical named-entity recognition, and external knowledge bases to build knowledge graphs. Applied to recent chemistry literature, this approach minimizes overlap with LLM pretraining data. The resulting dataset comprises 1,188 multi-hop questions, refined through domain-expert feedback and robust evaluation protocols.Using ChemComp, we systematically compare LLM performance with and without retrieval augmentation, including an idealized gold-context scenario. Our results show that even state-of-the-art models struggle with compositional reasoning: retrieval significantly improves accuracy, yet reasoning errors persist even under perfect retrieval. These findings highlight the limitations of current LLMs and the critical role of retrieval-augmented methods in scientific reasoning. Furthermore, our pipeline is generalizable with fine-tuning, enabling the creation of challenging multi-hop reasoning benchmarks across domains and proprietary datasets.- Anthology ID:
- 2026.findings-eacl.322
- Volume:
- Findings of the Association for Computational Linguistics: EACL 2026
- Month:
- March
- Year:
- 2026
- Address:
- Rabat, Morocco
- Editors:
- Vera Demberg, Kentaro Inui, Lluís Marquez
- Venue:
- Findings
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 6117–6143
- Language:
- URL:
- https://preview.aclanthology.org/ingest-eacl/2026.findings-eacl.322/
- DOI:
- Cite (ACL):
- Mohammad Khodadad, Ali Shiraee Kasmaee, Mahdi Astaraki, Nicholas Sherck, Hamidreza Mahyar, and Soheila Samiee. 2026. Evaluating Multi-Hop Reasoning in Large Language Models: A Chemistry-Centric Benchmark. In Findings of the Association for Computational Linguistics: EACL 2026, pages 6117–6143, Rabat, Morocco. Association for Computational Linguistics.
- Cite (Informal):
- Evaluating Multi-Hop Reasoning in Large Language Models: A Chemistry-Centric Benchmark (Khodadad et al., Findings 2026)
- PDF:
- https://preview.aclanthology.org/ingest-eacl/2026.findings-eacl.322.pdf