Oracle-Budgeted Molecular Optimization with Short-Term Graph Memory
This work addresses the challenge of efficiently selecting high-potential candidate molecules under a limited oracle query budget in molecular optimization. The authors propose a plug-in short-term graph memory mechanism that, without altering the generator architecture, incrementally constructs a graph neural network surrogate model from previously evaluated molecules to prescreen candidates and prioritize those with higher predicted utility for oracle evaluation. This approach incurs no additional oracle calls yet significantly enhances optimization efficiency. Experimental results demonstrate that, under a stringent budget of only 1,000 oracle queries, the method consistently outperforms the original strategy across four fragment-based generators, substantially improving the average top-10 score without any observed performance degradation, while also revealing systematic interactions between the generator’s exploration–exploitation behavior and surrogate-guided selection.