Pharmaceutical solid dosage forms are composed of powders whose quality and performance are based on the foundational solid-state chemistry defining the form in which the particles exist. Understanding the behavior that emanates from the molecular matrix and final morphology is central to establishing the reproducibility of key quality and performance metrics. The compositional and structural characteristics of the solid represent the spatial physicochemical factors with implications for potential temporal chemical and physical effects. Characterizing these properties may be used to establish the initial and final state of a solid with respect to a process which may be connected to product quality and performance. These properties partially define expectations of stability, dissolution, and bioavailability, which in turn relate to safety and efficacy. Occasionally, particles exist with disordered, amorphous, molecular structure. Most frequently ordered systems exist that are defined by uniform distances between adjacent molecules that define the general morphology of the crystal system. However, the particle appearance may vary based on constraints of crystal growth or the presence of impurities.