presence of a lower laying pp* state (S1), for which the symmetry allowed transition yields a high oscillator strength, and a darker np* state (S2). Note that, coherently with what reported elsewhere the two states appears quasi-degenerate and have an excitation energy of about 3.7 and 3.9 eV, respectively. Note also that because of the high difference in the relative oscillator strength 2.048 vs 0.002 one may safely assume that the photophysics of enol CURC can be inferred considering the initial population of S1, only. An extended benchmark reporting the excitation energies calculated with different functionals and basis set can also be found in Electronic Supplementary Information (ESI). Note that, as shown in a previous contribution, the manifold of the singlet excited states for keto CURC will be more complicated due to the breaking of symmetry leading to an ensemble of mixed quasi-degenerate states having similar oscillator strength. As shown in Figure the simulated absorption spectrum of enol CURC, calculated at TD-DFT level, is only moderately sensitive to the size and type of the basis set, hence justifying the use, especially for the subsequent SH dynamics the smaller 6-31G base. On the contrary, a more marked dependency on the functional nature and type can be observed with PBE0 providing a highly red-shifted transition, while long-range corrected functionals behave coherently among them. In particular hybrid functional are also artificially lowering the energy of the np* state, due to its partial charge-transfer character which can be appreciated from the low value of the fS descriptor (~0.3) indicating a small overlap between hole and electron densities.