Distinguishing types of disorder in diffuse scattering: A numerical simulation study

Using numerical simulation tools such as DISCUS and ZMC, the signatures in simulated pair distribution function (PDF) and single-crystal diffuse scattering (SCDS) of various types of disorders in a range of model systems are explored by observation of the evolution of calculated PDF and SCDS. Disordered crystalline materials may show a variety of types of short-range correlations in occupancies, displacements, and (if a molecular system) orientations of constituents. Further, the correlation between occupancy and displacement (the size effect) will often also be present. This work provides some insight into the abilities of the two data types to distinguish and quantify these different aspects of disorder in materials, with a view to guide the analysis of real systems.