Powder X-ray diffraction is a standard method of identifying crystal structures.
Mean-square atomic displacement <u2> values can be experimentally obtained from various measurements, such as thermal expansion, thermal conductivity, extended x-ray absorption fine structure (EXAFS) and the widths of the x-ray or neutron diffraction peaks.
High-resolution powder XRD data can be collected using a synchrotron radiation source (e.g. λ = 0.41222 Å).
Note that the RDF analysis is important for the study of non-crystalline
solids. The RDFs can be experimentally measured after Fourier transformation of neutron or electron diffraction or X-ray diffraction (XRD) data.