CHIMERA-4B-RL is
CHIMERA-4B-SFT further trained with reinforcement learning on the
CHIMERA dataset.
CHIMERA is a compact synthetic reasoning dataset comprising 9K samples designed for generalizable cross-domain reasoning. It provides rich, long Chain-of-Thought (CoT) trajectories across 8 major scientific disciplines. Despite its modest size, post-training a 4B model on this data allows it to approach or match the reasoning performance of significantly larger models like DeepSeek-R1 and Qwen3-235B.
1@article{zhu2026chimera,
2 title={CHIMERA: Compact Synthetic Data for Generalizable LLM Reasoning},
3 author={Zhu, Xinyu and Feng, Yihao and Sun, Yanchao and Du, Xianzhi and Li, Pingzhi and Saarikivi, Olli and Zhu, Yun and Meng, Yu},
4 journal={arXiv preprint arXiv:2603.00889},
5 year={2026}
6}
