A similar work performed an analysis of the ground state of formaldehyde with scQED-HF. 149 Fig. shows the (left) HOMO and (right) LUMO+1 for the molecule coupled inside the cavity (bottom) and for the bare molecule outside the cavity (top). The cavity frequency was set to ω c = 10.4 eV with coupling strength λ = 0.1 a.u and polarization ê = ŷ + ẑ (see Fig. for Cartesian axes). Here, the authors make note of the loss in the symmetry of the MOs resulting from the influence of the cavity. The overall symmetry of the molecule changed from C 2v to C s after orbital relaxations under influence from the cavity. The bare molecular system contains a HOMO with 2B 2 symmetry and LUMO+1 with 6A 1 symmetry. Upon coupling to the cavity, the MOs become distorted (similar to what was seen in the previous example Fig. ) and take on new types of symmetry with labels 7A' and 8A', respectively. The LUMO+1 state has the most visually obvious effects in that the p-orbital on the oxygen (left-most atom) rotates to becomes parallel with the polarization direction, while the other part of the orbital changes shape entirely with the dominating part of the orbital lying in-line with the oxygen p-orbital rather than symmetrically split according to the symmetry of the nuclei. These modifications to the frontier orbitals showcase the drastic effects the cavity may have on local reactivity of the molecules whereby the molecular orbitals exchange character and lead to various changes to the local electrostatic potential and atomic charges. In the same work, the configuration interaction (CI) theory is also developed for the sc-QED method, which is convenient for incorporating electronic-photonic correlations for calculations of the excited states.