For polaritonic systems, the PICI can form when the orientation of a molecule's ground-to-excited transition dipole moment becomes orthogonal to the cavity polarization vector such that θ = π/2, and the lightmatter coupling vanishes at this orientation. Thus, one can see that even for a diatomic molecule where there are no intrinsic electronic CIs, there will be a PICI due to the presence of the additional DOF, i.e., the angle θ between the dipole and the field polarization direction. This angle serves as the tuning coordinate in the CI. One can thus engineer a new CI that did not exist pre-viously by coupling molecules with a cavity. These CIs, either intrinsic or cavity-induced, lead to a singularity in the non-adiabatic coupling (see Eq. 23) and thus cause a breakdown of the Born-Oppenheimer approximation in the vicinity of the CI. Unlike those intrinsic molecular CIs, cavity-induced CIs depend on the properties of the cavity and can thus be tuned to control photochemical reactivity.