These cavity-induced effects can be clearly demonstrated using simple single-molecule model reactions, which is ideal for an experimental setup with certain plasmonic cavities 20 (see Fig. ). One of the simplest photochemical reactions is that of bond photodissociation. The primary mechanism of this reaction is a Franck-Condon photoexcitation of a molecule to a molecular excited state, which has a curvature that pushes the nuclei away from the bonded regime and towards the dissociated regime. Absent this photoexcitation, the nuclear wavepacket remains in the equilibrium geometry of the ground state potential and resists dissociation. How exactly to translate this PES hybridization principle into the collective coupling regime is still an open question, and the recent progress along this direction will be discussed in Sec. 6.3.