Measurements and scaling of X-ray total scattering from single crystals

Abstract: We present a measurement protocol and a data reduction workflow for obtaining single-crystal X-ray total-scattering datasets that capture both Bragg-peak and diffuse scattering intensities on an absolute (electrons2/atom) scale. We further demonstrate that the intensity scale factor derived from crystallographic refinements using Bragg peaks is in close agreement with that obtained by matching the scattering function, computed via spherical integration of the 3D total scattering signal, to the theoretical coherent baseline, calculated as the spherical average of the Debye-Waller factor. The latter approach can be applied to diffuse scattering without including Bragg peaks. Our results set the ground for structural refinements using large atomic configurations while simultaneously fitting Bragg intensities and diffuse scattering from a single crystal. Moreover, with the convergence between the two scaling methods, the Bragg and diffuse components can be obtained from the same total-scattering dataset, as achieved in this work, or measured independently.