ChemVLR: Prioritizing Reasoning in Perception for Chemical Vision-Language Understanding

Xuanle Zhao, Xinyuan Cai, Xiang Cheng, Xiuyi Chen, Bo XU


Abstract
While Vision-Language Models (VLMs) have demonstrated significant potential in chemical visual understanding, current models are predominantly optimized for direct visual question-answering tasks. This paradigm often results in "black-box" systems that fail to utilize the inherent capability of Large Language Models (LLMs) to infer underlying reaction mechanisms. In this work, we introduce ChemVLR, a chemical VLM designed to prioritize reasoning within the perception process. Unlike conventional chemical VLMs, ChemVLR analyzes visual inputs in a fine-grained manner by explicitly identifying granular chemical descriptors, such as functional groups, prior to generating answers. This approach ensures the production of explicit and interpretable reasoning paths for complex visual chemical problems. To facilitate this methodology, we implement a cross-modality reverse-engineering strategy combined with a rigorous filtering pipeline to curate a large-scale reasoning and caption dataset, comprising 760k high-quality samples across molecular and reaction tasks. Furthermore, we adopt a three-stage training framework that systemically builds model perception and reasoning capacity. Experiments demonstrate that ChemVLR achieves state-of-the-art (SOTA) performance, surpassing both leading proprietary models and domain-specific open-source baselines. We also provide comprehensive ablation studies to validate our training strategy and data generation designs.
Anthology ID:
2026.findings-acl.1206
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
24096–24115
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1206/
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Cite (ACL):
Xuanle Zhao, Xinyuan Cai, Xiang Cheng, Xiuyi Chen, and Bo XU. 2026. ChemVLR: Prioritizing Reasoning in Perception for Chemical Vision-Language Understanding. In Findings of the Association for Computational Linguistics: ACL 2026, pages 24096–24115, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
ChemVLR: Prioritizing Reasoning in Perception for Chemical Vision-Language Understanding (Zhao et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1206.pdf
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