Retrieval-Retro: Retrieval-based Inorganic Retrosynthesis with Expert Knowledge
Heewoong Noh, Namkyeong Lee, Gyoung S. Na, Chanyoung Park
TL;DR
Retrieval-Retro addresses the challenge of inorganic retrosynthesis by retrieving reference materials with MPC and NRE retrievers and then implicitly extracting precursor information through attention-based fusion, guided by thermodynamic domain knowledge. The method combines composition-graph representations with self- and cross-attention to fuse target and retrieved references, enabling novel synthesis recipes beyond known precedents. Empirical results show improved precursor prediction, especially under realistic year-split evaluations, with ablations highlighting the complementary roles of MPC and NRE and the value of implicit extraction. This approach advances automated planning for inorganic material synthesis and has potential to accelerate materials discovery by broadening feasible synthesis pathways.
Abstract
While inorganic retrosynthesis planning is essential in the field of chemical science, the application of machine learning in this area has been notably less explored compared to organic retrosynthesis planning. In this paper, we propose Retrieval-Retro for inorganic retrosynthesis planning, which implicitly extracts the precursor information of reference materials that are retrieved from the knowledge base regarding domain expertise in the field. Specifically, instead of directly employing the precursor information of reference materials, we propose implicitly extracting it with various attention layers, which enables the model to learn novel synthesis recipes more effectively. Moreover, during retrieval, we consider the thermodynamic relationship between target material and precursors, which is essential domain expertise in identifying the most probable precursor set among various options. Extensive experiments demonstrate the superiority of Retrieval-Retro in retrosynthesis planning, especially in discovering novel synthesis recipes, which is crucial for materials discovery. The source code for Retrieval-Retro is available at https://github.com/HeewoongNoh/Retrieval-Retro.
