In Figure it can be seen that the ωB97X-D3-calculated HOMO-LUMO gap and electronic energies agree with the GA and the GFN2-xTB-calculated values, as those oligomers indeed have a small singlet HOMO-LUMO gap and a stable triplet groundstate. This further shows that GFN2-xTB can be a good surrogate for DFT in finding oligomers with small HOMO-LUMO gaps with the GA. While most of the oligomers show similar electronic properties, two of them, one constructed from monomers 642 and 365 and another constructed from monomers 642 and 128, look like outliers. However, we expected to see some variation between the singlet HOMO-LUMO gap and the ∆E T -S since the correlation is not perfect. On the contrary, those two outliers are the two data points closest to the best-fit line calculated in the previous study .