Pair Distribution Function (PDF) analysis is a real-space structural analysis method that provides insight into the local atomic arrangement of materials. Unlike conventional diffraction, which relies primarily on long-range periodicity and Bragg peak analysis, PDF incorporates both Bragg and diffuse scattering to capture short-range order and local structural deviations. Applying the Fourier transform to the total scattering structure function, S(Q), in real space yields the function “G(r)”, which describes the probability of finding atomic pairs separated by distance r, relative to a random distribution.

PDF analysis is particularly powerful for studying materials where disorder, defects, nanoscale crystallite size, or limited periodicity obscure or eliminate traditional diffraction features. It enables precise investigation of local coordination environments, bond lengths, strain fields, cluster size effects, and defect-induced distortions, which are critical parameters in complex and functional materials.