We also looked to trends in the predictions in order to see if there are monomers that repeatedly contribute to oligomers with low λ (Figure ). For both tetramers and hexamers, the monomers number 47, 110, 158, 213, 258, and 283 are found frequently (Figure ). As it can be seen, all the best performing monomers have a fused aromatic system on the thiophene backbone, supporting our hypothesis that a larger πsystem contributes to low λ. Moreover, exclud-ing monomer 253 which only has one, all of the monomers have two aromatic nitrogen atoms in the 3-and 4-positions on the thiophene ring. We hypothesize that steric considerations contribute, as CH 2 groups in these positions increase the steric repulsion between neighboring monomers forcing a non-planar, twisted chain conformation and increasing λ 12 . In addition to that, monomers with similar motifs, such as nitrogen atoms in the 3-and 4-positions, and especially a thiadiazol group, have been shown to be pro-quinoidal monomers which has some quinoidal character instead of an aromatic one . This behavior contributes to a higher double bond character of the inter-ring bond, decreasing its length and restricting the rotation of the dihedral angle. This restrains the conformational change the oligomer undergoes upon a hole transfer, which contributes to a low λ.