C. Basis sets B3LYP/CIS calculations reported here use a bespoke basis set introduced by Grimme for this purpose. 9 Its construction starts from the valence triple-zeta (VTZ) basis set introduced by Ahlrichs and co-workers, then adds additional polarization functions: d-functions on carbon and p-functions on hydrogen, each with ζ = 0.8 a -2 0 . 9 For Rydberg states, this basis set was augmented with one set of diffuse sp-functions on each non-hydrogen atom, with exponents selected according to Dunning's procedure. (Full specification of this basis set is provided in the Supplementary Material.) Our CAM-B3LYP/CIS implementation is parameterized for use with def2-TZVPD, although we will also provide examples of CAM-B3LYP/ CIS used with the def2-SVPD and def2-SV(P) basis sets, in an effort to assess its sensitivity in that respect. All conventional CIS and TD-DFT calculations employ the def2-TZVPD basis set.