Even more recently, we provided accurate reference excitation energies for transitions involving a substantial amount of double excitation using a series of increasingly large di usecontaining atomic basis sets. Our set gathered 20 vertical transitions from 14 small-and medium-size molecules (acrolein, benzene, beryllium atom, butadiene, carbon dimer and trimer, ethylene, formaldehyde, glyoxal, hexatriene, nitrosomethane, nitroxyl, pyrazine, and tetrazine). For the smallest molecules, we were able to obtain well converged excitation energies with augmented quadruple-ζ basis set while only augmented double-ζ bases were manageable for the largest systems (such as acrolein, butadiene, hexatriene and benzene). Note that the largest sCI expansion considered in this study had more than 200 million determinants.