Fig. 2: Powder patterns derived from XFEL data.
From: Chemical crystallography by serial femtosecond X-ray diffraction
a, b, A histogram over thousands of individual Bragg spot observations identifies the d spacings of the lattice, expressed here as the diffraction angle 2θ (in °). As described in Methods section ‘Synthetic powder patterns from XFEL shots’, first the spots are found from the full dataset, then the spot positions are converted to d spacings. The d spacings are then binned into a histogram that amounts to a sharpened powder diffraction pattern. c–e, Radial averages of thiorene (c), mithrene (d) and tethrene (e) using the spot-finder radial histogram (black) compared to laboratory source XRD patterns (coloured). The horizontal axis is scaled to the wavelength of Cu Kα radiation (λ = 1.5406 Å), according to Bragg’s law (λ = 2dsinθ), and the vertical axes are shown in arbitrary units. Thiorene was affected by an unknown impurity in low concentration and thus weak reflections have been downweighted. Insets show magnification of the data around 2θ = 37°–43°.
