In another work, 157 the authors use the scQED-HF and the scQED-CCSD-1-21 approaches (see Sec. 3.2) to explore the effects of adding (i.e., electron affinity) or removing (i.e., ionization potential) from sodium halide molecules coupled to the cavity 157 Specifically, Fig. shows the ground state electronic density difference, defined as ∆ρ qq = ρ pl q -ρ el q where q is the total charge in the system, ρ pl q is the ground state density inside the cavity, and ρ el q is the ground state density of the bare molecular system. As shown in Fig. , the bond of the NaF molecule can be destabilized upon insertion into the cavity and further destabilized if the molecular system is negatively charged. The results of the ground state difference density function evaluated in the plane of the molecule are shown in Fig. with the coupling strength λ = 0.05 a.u. and with the cavity polarization along the Na-F bond vector (panels i and ii) and perpendicular to the bond vector (panels iii and iv). Further, panels (i) and (iii) are for a neutral system, and panels (ii) and (iv) are for a negatively charged system. The red color indicates an increase in the electron density upon coupling to the cavity, whereas the blue color indicates a decrease in electron density. For the neutral systems, when setting the cavity polarization along the bond (panel i) or perpendicular to the bond (panel iii), it was found that there is a relatively small change of the electron density, except at positions very close to the nuclei. In both cases, the electronic density differences showcase a p-orbital-like increase in density with the same polarization as the cavity. In panel (i), there is a small reduction in electron density (blue color) between the Na and F nuclei, indicating a reduction in bonding character. It is clear from the electronic redistribution in both polarization directions (i,iii) that the stability and bonding character of the NaF system is significantly modified, which will lead to changes in the ground state dissociation of these molecules. Fig. (ii) and (iv) present the same type of analysis but for a negatively charged species (NaF) -. Here, the electronic redistribution is more drastic, and at larger distances from the atomic centers, there is a less noticeable impact from the polarization direction. In both cases of the cavity polarizations, a large addition of electron density can be seen below the Na atomic center, more prominent in the case of perpendicular polarization (iv). This indicates that the cavity is able to significantly redistribute this additional electron from three places: (I) close to the nuclei, (II) between the Na-F bond, and (III) far-away (light blue > 2 Å from Na nucleus). In all four cases, the bonding character is expected to be reduced while a major electron density reorganization is seen for the negatively charged molecule. This work demonstrated the capacity of the scQED-CC method for investigating the electron affinity and ionization potentials of various small systems and provided simple physical explanations of the cavity-induced effects through the ground state density difference function.