Using Equation , Tsai and co-workers studied internal conversion occurring in some anthracene derivatives and perylene within a cavity, and were able to demonstrate that the electrodynamic internal conversion rate constant can be significantly perturbed by adjusting V , resulting in drastic changes to the light-matter coupling. For 9-cyanoanthracene, the combined internal conversion rate varied between 0.2-7×10 8 s -1 for a V range of a thousand to a million cubic nanometers, while for perylene it varied between 1.5-100×10 6 s -1 for V between five thousand to three and a half million cubic nanometers. Lower values of V also result in dominant W cavity terms, with this property more apparent in perylene than 9-cyanoanthracene. At certain effective mode volumes, internal conversion of the system was found to equal internal conversion due to the cavity W system = W cavity , for which an analytical expression for this crossing point was found . For 9-cyanoanthracene this is around fourty thousand cubic nanometers, while for perylene it is around two hundred thousand cubic nanometers. Experimental V values seen in the literature vary greatly , between a hundred to a hundred million cubic nanometers; therefore even simple cavity manipulation is a viable method to control internal conversion. It is also worth noting that while based on Equation 14 one would assume that even in a cavity, vibronic coupling would be the driving force of internal conversion, instead the orientation of each normal mode with respect to the polarisation axis can have a powerful effect.