"Ultima Ratio": Simulating wide-range X-ray scattering and diffraction

• DOI: 10.48550/arxiv.2303.13435
• Publication Date: 2023-01-01
• Authors: Brian R. Pauw; Sofya Laskina; Aakash Ashok Naik; Glen J. Smales; Janine George; Ingo Breßler; Philipp Benner
• Keywords: Small-angle X-ray scattering; Intensity; Pair Distribution Function

We demonstrate a strategy for simulating wide-range X-ray scattering patterns, which spans the small- and wide angles as well typically used Pair Distribution Function (PDF) analysis. Such simulated patterns can be to test holistic analysis models, and, since diffraction intensity is on same scale intensity, may offer novel pathway determining degree of crystallinity. The "Ultima Ratio" demonstrated 64-nm Metal Organic Framework (MOF) particle, calculated from Q < 0.01 1/nm up 150 1/nm, with resolution 0.16 Angstrom. computations exploit modified 3D Fast Fourier Transform (3D-FFT), whose modifications enable transformations matrices at least 8000^3 voxels in size. Multiple these 3D-FFTs are combined improve low-Q behaviour. resulting curve compared pattern measured polydisperse MOF powder. While computationally intensive, approach expected useful range realistic, complex structures, (poly-)crystalline particles hierarchical, multicomponent structures such viruses catalysts.