# MolP2SBench

MolP2SBench recasts molecular property-to-structure inference as masked-scaffold multiple choice and adds shuffled and counterfactual property substitutions, separating a correct answer from genuine use of the supplied evidence. Across seven models, accuracy on a property channel does not track how strongly a model responds when that property is replaced, and model performance does not always match chemists' intuition about which properties are easier.

MolP2SBench recasts molecular property-to-structure inference as masked-scaffold multiple choice and adds shuffled and counterfactual property substitutions, separating a correct answer from genuine use of the supplied evidence. Across seven models, accuracy on a property channel does not track how strongly a model responds when that property is replaced, and model performance does not always match chemists' intuition about which properties are easier.