As shown in Figure we may indeed evidence that not only the S1 state PES may cross one of the triplet (T4), but at its equilibrium region it also lays close in energy, and more importantly evolves in parallel, with the PES of T2 and T3. Such an arrangement, which is coherent with the one observed previously, may be indicative of a possible ISC, which however should not be ultrafast due to the necessity to overcome some barriers or to allow for the vibrational induced inversion between the energy of the quasi-degenerate singlet and triplet states. Note also that favourable ISC channel may exist also from S2, however due to the very low oscillator strength it is unlikely that they could play a major role in CURC photophysics.