Before analyzing energy landscapes for the molecules in Fig. , we first scrutinize the degree of density-driven error in these systems, as it has been observed that DC-DFT offers a better solution than conventional (selfconsistent) DFT only when the density-driven error is large. (Systems with significant static correlation also do not benefit from DC-DFT, which is consistent with the idea that SIE may sometimes masquerade as strong correlation. ) We use the metric S in Eq. ( ), evaluated using the SCAN functional, to assess density sensitivity. Based on small-molecule results, S > 8 kJ/mol has been suggested as a threshold beyond which DC-DFT is likely to improve the results. Table provides values of S for various molecules considered in this work, computed as an average over all conformers since the variations from one conformer to the next are 2 kJ/mol. (Differences in S from one conformer to the next will be considered later.) We obtain values ranging from S = 124-528 kJ/mol although our molecules are considerably larger than the ones used to set 8 kJ/mol as the threshold value. It has also been suggested that that S is not a size-extensive metric until the system is large enough for delocalization to attenuate naturally. (In an infinite conjugated polymer described by a GGA functional, it is not clear that the delocalization length must ever terminate, as has been demonstrated for excitons described by time-dependent DFT with semilocal functionals. ) For the molecules considered here, the size-normalized metric S atom [Eq. (7)] is as large as 7.6 kJ/mol. We will see that all of these molecules are affected by π-delocalization error, thus the 8 kJ/mol threshold (even if applied to S atom ) does not appear to be a sufficient diagnostic.