Data from: Resolving the dynamic correlated disorder in KTa1-xNbxO3

This is the data for the publication "Resolving the Dynamic Correlated Disorder in KTa1−xNbxO3" that has been accepted by Proceedings of the National Academy of Sciences. The numerical data were used to generate the figures 1 to 5 in the main text of the publication. All the data are in text format except four of them are h5 format. Experimental data were collected through inelastic neutron scattering and diffuse neutron scattering experiments conducted at Oak Ridge National Laboratory. Simulation data were generated by density functional theory, ab initio molecular dynamics, and machine-learning molecular dynamics simulations.
The abstract of the publication is "Understanding the complex temporal and spatial correlations of ions in disordered perovskite oxides is critical to rationalize their functional properties. Here, we provide new insights into the longstanding controversy regarding the off-centering of transition metal ions in the archetypal ferroelectric alloy KTa1−xNbxO3 (KTN). By mapping the full energy (E) and wavevector (Q) dependence of the dynamical structure factor S(Q, E) using neutron scattering, and rationalizing our observations with atomistic simulations leveraging machine learning, we fully resolve the static vs dynamic nature of diffuse scattering sheets, as well as their composition (x) and temperature dependence. Our first-principles simulations, extended with machine-learning molecular dynamics, reproduce both inelastic neutron spectra and diffuse features, and establish how dynamically-correlated transition metal off-centerings couple to phonons, unifying local and collective viewpoints. This study sheds new light into an exemplary ferroelectric systems and shows the importance of mapping the full S(Q, E) to reveal critical spatio-temporal correlations of atomic disorder from which functional properties emerge."