Ref. 195 uses an ab-initio QEDFT (see details in Sec. 3.2.4) approach to investigate a chain of nitrogen dimers within a cavity. They find that collectively coupling all nitrogen dimers (with the same nuclear configuration) can modify the potential energy surface for small perturbations along the dissociation coordinate of one molecule in the vicinity of the uniform (such that all molecules have identical nuclear configuration) configuration. The effect of a small perturbation to one molecular nuclear configuration on the collective coupling is illustrated in Fig. . For identical molecules with uniform nuclear configurations, the collective cavity coupling gives N -1 dark states and 2 polaritonic (upper and lower) bright states (as shown in Fig. and Fig. ). For one molecule perturbed, as schematically shown in Fig. (left panel), an additional polariton state appears as molecular excitation on one molecule (the perturbed one) is off-resonant to the molecular excitations on the rest of the molecules or cavity photon frequency. To understand this consider the rest of the N -1 molecules collectively coupled to a cavity to form upper polariton, lower polariton, and N -2 degenerate dark states, which corresponds to the higher energy levels in Fig. . The perturbed molecular excitation (lying energetically lower) then weakly couples to the upper and lower polaritons. As a result, there are four types of light-matter states, in ascending order of energy they are, (a) an upper polariton composed of N -1 (unperturbed) molecular excitation, the cavity excitation (1 photon in the cavity), and of a relatively tiny fraction of the perturbed molecular excitation, (b) a set of N -2 dark states composed of only N -1 (unperturbed) molecular excitations, (c) a middle polariton with a similar composition as the upper polariton except for a relatively higher contribution (still tiny) from the perturbed molecular excitation, and (d) the lower polariton pre-dominantly composed of the perturbed molecular excitation with a relatively low component of the other molecular and cavity excitations. It is the modification of the lower polariton that will lead to a modification of local chemical reactivity. The authors report, for the few molecules coupled to a cavity considered in their study, this lower polariton can indeed be modified by collective coupling to the rest of the molecules. However, the extent of the modification of this lower polariton is also limited by the light-matter coupling of a single molecule. Thus, when a single molecular coupling to the cavity is vanishingly small, such modification of a single molecular potential is unlikely regardless of how strongly the rest of the molecules are coupled to the cavity.