In what follows we report on BSE@GW and TDDFT (B3LYP) electronic excitation spectra for OPBE, B3LYP, and MP2 geometries. Kohn-Sham orbitals obtained with the B3LYP functional were used as an initial guess for the BSE@GW calculations. The CD method was used in the BSE@GW case to limit the number of quasiparticle energies calculated and consequently the computational effort. Fortunately, this reduction does not lower the quality of the results, as demonstrated in the Supplementary Material Section S1. Since for the experimental spectra only the absorption strength and wavelengths had been reported in Ref. 50. All spectra in Fig. were uniformly broadened. The assignment of the spectra in terms of an analysis of the TDM is given in Fig. . Normalized Intensity [1] Energy ] N + , using different central metals, levels of theory, and equilibrium geometries. All entries are sorted by the level of theory used to calculate the spectrum, followed by the method used to generate the geometry. All spectra were obtained using the B3LYP functional. The experimental stick spectrum from Ref. 50 has been broadened using a Lorentzian with a width of 0.25 eV (gray area).