In addition to the correlation between the singlet HOMO-LUMO gap and the stability of the triplet state, we also previously found a correlation between the singlet HOMO-LUMO gap calculated using density functional theory (DFT) and the HOMO-LUMO gap calculated using the semi-empirical GFN2-xTB method. While the correlation is imperfect, there is a clear trend. To strengthen the correlation, we calculated the HOMO-LUMO gap using both GFN2-xTB and ω B97X-D3 of randomly generated list of new oligomers from the expanded list of monomers used in this study (Figure ). See Section 2.3.2 for how these calculations were performed.