Along the same vein, Fig. also uses the scQEDbased approach to investigate the ground state proton transfer reaction in the symmetric malonaldehyde (top) and asymmetric aminopropenal (bottom) molecules. Here, the cavity frequency was set to 3.0 eV with lightmatter coupling λ = 0.10 a.u. The ground state energy at the transition and product (for the asymmetric molecule) geometries, both of which are relative to the reactant energy, were computed using a variety of scQED methods, including QED-CC (blue), QED-HF (red), and QED-DFT (green). The reaction profile outside the cavity (solid lines) is also calculated using the corresponding level of the theory. Inside the cavity (dashed lines), for both molecules (top and bottom panels) and for all levels of theory, the reaction barrier height is increased by nearly ∼1 kcal/mol (top panel) and ∼0.85 kcal/mol (bottom panel) when coupling molecule with the cavity. For the aminopropenal molecule (bottom panel) the product was only changed by ∼0.1 kcal/mol for the QED-CC method and ∼1.0 kcal/mol for QED-DFT and QED-HF. This evi-