Elisa Pieri, University of North Carolina, Chapel Hill: "Can we automate in silico photoreaction discovery?" (host: Walker)

Abstract: In the field of photochemistry, the role of theoretical chemistry in designing new photoactive molecules is increasingly significant, driven by enhanced computational capabilities and the data science revolution. Consequently, grasping the mechanisms governing photochemistry is critical for effective theoretical molecular design. While nonadiabatic molecular dynamics is the technique of election for predicting photochemical outcomes, its computational demands can be substantial (especially in the context of proteins and fluorescent probes), often necessitating prior knowledge of the photochemistry under investigation. Addressing this challenge, we present and discuss the Nonadiabatic Nanoreactor, a novel tool that autonomously reveals a molecule's photoproducts without relying on prior reaction information. Our method extensively samples the intersection space between two electronic states via seam-constrained metadynamics, pinpointing key conical intersections, which are then linked to accessible photoproducts. We demonstrate the tool's efficacy on benzene and cyclopentenones, identifying both common and rare photoproducts. Consequently, the tool serves as a valuable diagnostic and supplementary resource to nonadiabatic dynamics. Furthermore, it paves the way for high-throughput screening of (macro)molecules, offering insights into the design of light-driven molecular systems.