 In this study, researchers used an exact quantum dynamics approach to investigate a model of cavity-modified chemical reactions in the condensed phase. They found that when a molecule is coupled to an optical cavity, it is necessary to treat the problem quantum mechanically to obtain a quantitative account of alterations to reactivity. Quantum mechanical state splitings and resonances were identified as key factors in determining the rate of chemical reactions. These results are closer to experimental observations than previous calculations, even for realistically small values of coupling and cavity loss. This work highlights the importance of a fully quantum treatment of vibrational chemistry. This article was authored by Lachlan P. Lindowie, Arkeget Mundel and David R. Rackman.