In addition to creating new conical intersections, coupling molecules that have an intrinsic electronic CI to cavities can split the original CI into two CIs, each having a mixed character of electronic excitation and photonic excitation, as described in the work shown in Fig. , adapted from Ref. 227. As shown in Fig. (i), when a model pyrazine molecule with an intrinsic CI between two molecular excited states is coupled to a cavity, such that one of the molecular excited states experiences light-matter coupling, two CI appear among the 3 excited state surfaces with properties different from those of either an intrinsic CI or an isolated PICI (Fig. ). The locations of both CIs vary with the light-matter coupling strength, and as the light-matter coupling increases (from Fig. (i) to c(ii)), the distance between these two CIs also increases. This is in contrast to the individual PICI in Fig. whose location is independent of light-matter coupling strength. This feature of polariton-induced CIs allows for tunability of the CI position and thus a more flexible control over photochemical reactions that involve polaritoninduced CIs. The geometric phase effects caused by these CIs can be seen in the nuclear probability density distribution in Fig. (iii)-(iv). The nuclear density is more spread out when outside the cavity (Fig. (iii)) than when coupled to the photonic mode inside the cavity (Fig. (iv)). This is consistent with the fact that the cavity coupling causes less energy to be stored in the vibrational modes and more to be stored in the cavity photonic mode. Additionally, the presence of lightmatter coupling has pushed the polariton-induced CI closer towards the Franck-Condon position which enhances the Berry phase-induced destructive interference seen at the coupling nuclear coordinate Q c = 0 (not to be confused with the cavity q c ) in Fig. (iv). These effects ultimately influence the electronic-photonic population dynamics, allowing for cavity control of these molecular systems that contain intrinsic CIs.