Orientational Effects in the Low Pair Continuum of Aluminium
Abstract
We compare the predictions of the dynamic structure factor (DSF) of ambient polycrystalline aluminium from time-dependent density functional theory (TDDFT) in the pair continuum regime to recent ultrahigh resolution x-ray Thomson scattering measurements, collected at the European XFEL. TDDFT predicts strong anisotropy in the DSF at the wavenumber examined here, even with -blurring accounted for. The experimental spectrum has more than sufficient resolution and signal-to-noise levels to resolve these orientation dependencies, and therefore the orientational averaging of the polycrystalline sample is observed rigorously. Once the orientation averaging is accounted for, TDDFT is able to reproduce the experimental spectrum adequately. Finally, comparisons of predicted DSFs from jellium to experiment demonstrates the importance of accounting for lattice effects in modelling the spectrum from a polycrystal.
Keywords
Cite
@article{arxiv.2508.02251,
title = {Orientational Effects in the Low Pair Continuum of Aluminium},
author = {Thomas Gawne and Zhandos A Moldabekov and Oliver S Humphries and Motoaki Nakatsutsumi and Sebastian Schwalbe and Jan Vorberger and Ulf Zastrau and Tobias Dornheim and Thomas R Preston},
journal= {arXiv preprint arXiv:2508.02251},
year = {2025}
}