Quantitative and bond-traceable resonant X-ray optical tensors of organic molecules

2025/09/01 by Victor Murcia, Obaid Alqahtani, Murcia, Victor +5
Physics and Astronomy · Engineering · #Advanced X-ray Imaging Techniques #X-ray Spectroscopy and Fluorescence Analysis #Fiber-reinforced polymer composites

paper · pdf · doi:10.48550/arxiv.2509.01734

Abstract

X-ray scattering at the carbon absorption edge is uniquely sensitive to local molecular bond identity and orientation in organic nanostructures, encoded as a function of photon energy and polarization. However, quantitative analysis is precluded due to the lack of accurate optical models with bond and orientation specificity. We generate such a model through an algorithm that parameterizes and refines density functional theory calculations with angle-resolved absorbance spectroscopy measurements. The resulting optical tensor is shown to reproduce data from samples with domains of different orientation and crystalline packing, enabling label-free orientation analyses of individual chemical moieties within molecular nanostructures using resonant X-rays.

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