Finally, we examine the popular chemical motifs found by the GA in each of the property searches. Looking at the most commonly used monomers in the top 10% by fitness across all runs of each property search, we saw some common themes. As shown in Figure , the top monomers for polarizability are notably longer, larger molecules than those found in the other two property searches. This makes chemical sense considering that longer conjugated systems allow for greater charge mobility and therefore greater polarizability. While the top monomers for the optical bandgap search do not share especially close motifs, we know that extended conjugation, such as having a vinylene group on unit 273, redshifts the absorption and decreases the bandgap .