Obviously, CCSD methods significantly outperform the other methods in all the indicators considered independently if the Q or E formalism is employed. Q-CCSD is the most accurate method with a MAE of 5.7, a MSE of 0.1, and a SDE of 15.6. Similarly, E-CCSD reproduces Q-CC3 references well though with slightly deteriorated accuracy compared to the more costly Q-CCSD, with a MAE of 7.9, a MSE of 3.9, and a SDE of 17.7; these differences can be mainly ascribed to the valence states (see below). Conversely, Q-CC2 and I-ADC2 methods exhibit similar but significantly inferior performances than CCSD, with MAEs of 21.5 (22.8) for Q-CC2 (I-ADC2), over four times larger than the Q-CCSD value. Moreover, they demonstrate a quite large overestimation of 𝛿 TPA , resulting in a MSE of 20.2 (18.8) and a large error spread with SDE of 49.7 (34.4) for Q-CC2 (I-ADC2). Among the tested TD-DFT methods, we observe, as expected, different results based on the type of functional and the amount of exact exchange included. The most accurate methods are