This chapter provides a brief summary of computational materials science approaches utilized to direct and guide experimental studies in assessing the risk of identifying a more stable active pharmaceutical ingredient (API) crystal form, while providing a rationale at the molecular level to justify the selection of the optimal form and particle for robust drug product development. It focuses on drawing the attention to the wealth of information inherent in the structural features of the particles, and highlights a potential utilization of such a molecular toolbox during drug product design. Through the integration of these tools during development, a fundamental understanding of the relationship between molecular interactions, surface chemistry, and bulk properties makes it possible to identify the stable solid form as well as engineer the optimal crystal morphology for drug product processing and stability irrespective of the dosage form.