Table 2.
Tabulated values of singlet first excitation energies of six Thiel-set molecules (column 1) for which the agreement between computational and experimental results (column 4) was found to be particularly poor using XDFT using the PBE functional (column 2). The agreement is significantly improved by instead using the B3LYP hybrid functional (column 3). The last row of the table shows the Mean Absolute Error (MAE), which, in our case, is the same as the Mean Unsigned Error (MUE) of the XDFT results with respect to the experimental ones. All energies are in eV, and the multiplet sum method was used to simulate all single-particle singlet excitations.