Organic semiconductors (OSCs) are materials that possess the electronic features of semiconducting materials and the chemical and mechanical properties of organic compounds. OSCs are attractive materials due to their low-cost preparation, light weight, mechanical flexibility, easy processing, the ability to tune functions by molecular design, and rich availability compared to inorganic materials. For example, it is possible to achieve more π -π stacking, which leads to higher transport, by tuning substitutes of anthracene. Consequently, these materials have applications in flexible, printable, and scalable electronics, including light emitting diodes (LEDs), solar cells, transistors, thermoelectrics, sensors, and bioelectronics. OSCs are often in the form of molecular crystals, a class of materials held together by weak dispersion interactions. Due to the weak nature of these interactions, these materials are prone to exhibit polymorphism. Polymorphism is the ability of a molecule(s) to crystallize in more than one solid form. This phenomenon can arise from crystallization conditions, such as solvent, temperature, and pressure. Jurcheschu et al. used temperature to control the polymorphism of rubrene, resulting in crystal structures of different space groups and volume. Polymorphism can also impact the physicochemical properties of the system, such as band gap and charge transport. For example, Chung and Diao explored how polymorphism impacts the charge transport properties of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) and 2,7-dioctyl benzothieno [1]benzothiophene (C8-BTBT) and found that the packing motif highly impacted the amount of π -π stacking, which is correlated to the charge transport of the OSC. Li et al. similarly found that polymorphism can impact the bandgap of semiconducting polymers. Because the design space of organic molecular crystals can be large due to the number of packing motifs available to weakly interacting molecules, as well as the costs associated with traditional "trial and error" discovery methods, there has been increasing interest in using computational methods to predict if a candidate molecule will exhibit polymorphism and if so, which properties the polymorphs will possess.