Schwalbe et al. data publication: Static linear density response from X-ray Thomson scattering in warm dense beryllium, HZDR RODARE; Open access data.

Schwalbe et al. data publication: Static linear density response from X-ray Thomson scattering in warm dense beryllium, HZDR RODARE; Open access data.

Publications - Helmholtz-Zentrum Dresden-Rossendorf, HZDR

J. Vorberger et al., Roadmap for warm dense matter physics, Plasma Physics and Controlled Fusion (in print), arXiv:2505.02494

D. Bespalov et al., A Momentum-Resolved X-ray Thomson Scattering Benchmark of Electronic-Response Models in Warm Dense Aluminium, Physical Review Letters 136, 245102 (2026)

Zh. Moldabekov et al., Enhancing the efficiency of time-dependent density functional theory calculations of dynamic response properties, npj Computational Materials 12, 168 (2026)

L. Huang et al, Probing ultrafast heating and ionization dynamics in solid density plasmas with time-resolved resonant X-ray absorption and emission, Nature Communications 17, 3219 (2026)

D. Kraus et al., The structure of liquid carbon elucidated by in situ X-ray diffraction, Nature 642, 351-355 (2025)

T. Dornheim et al., Unraveling electronic correlations in warm dense quantum plasmas, Nature Communications 16, 5103 (2025)

“Online First” included Search title

Data publication: Static linear density response from X-ray Thomson scattering measurements: a case study of warm dense beryllium

Schwalbe, S. ; Bellenbaum, H. ; Döppner, T.; Böhme, M.; Gawne, T. D. ; Kraus, D. ; MacDonald, M.; Moldabekov, Z. ; Tolias, P.; Vorberger, J. ; Dornheim, T.

This repository contains the PIMC data shown in the publication “Static linear density response from X-ray Thomson scattering measurements: a case study of warm dense beryllium”.

Research data in the HZDR data repository RODARE Publication date: 2026-07-30 Open access DOI: 10.14278

Veröffentlichung im HZDR-Daten-Repository RODARE - Id 4889

Data publication: Reweighting Estimators for Density Response in Path Integral Monte Carlo: Applications to linear, nonlinear and cross-species density response

Svensson, P. ; Chuna, T. M. ; Vorberger, J. ; Moldabekov, Z. ; Hamann, P. ; Schwalbe, S. ; Tolias, P. ; Dornheim, T.

PIMC data for the uniform electron gas and scripts for extracting density response coefficients using the reweighting and ITCF methods presented in the associated paper.

Keywords: Nonlinear density response; Path integral Monte Carlo; Uniform electron gas

Research data in the HZDR data repository RODARE Publication date: 2026-07-03 Open access DOI: 10.14278

Veröffentlichung im HZDR-Daten-Repository RODARE - Id 4755

Data publication: Unlocking the Power of Orbital-Free Density Functional Theory to Explore the Electronic Structure Under Extreme Conditions

Ma, C.; Xi, Q.; Zhang, Z.; Wang, K.; Sun, Y.; Mi, W.; Moldabekov, Z. ; Dornheim, T. ; Vorberger, J. ; Schwalbe, S. ; Shao, X.

Research data presented in the paper ‘Unlocking the Power of Orbital-Free Density Functional Theory to Explore the Electronic Structure Under Extreme Conditions’ by Cheng Ma et al.

Keywords: warm dense matter; density functional theory; orbital free density functional theory

Research data in the HZDR data repository RODARE Publication date: 2026-06-26 Open access DOI: 10.14278

Veröffentlichung im HZDR-Daten-Repository RODARE - Id 4737

Thermal PBE in warm dense matter: Does it matter and is it accurate?

Ramakrishna, K. ; Lokamani, M. ; Moldabekov, Z. ; Dornheim, T. ; Burke, K.; Cangi, A.

Conditional probability density functional theory has recently been used to derive the temperature dependence of the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) for the exchange-correlation (XC) free energy. We implement and systematically benchmark thermal PBE within Kohn-Sham density functional theory calculations of warm dense matter. Comparisons with the local density approximation (LDA) and PBE functionals, as well as thermal LDA, show that thermal PBE significantly improves the description of warm dense matter properties, including energies, forces, pressures, and electronic charge densities. In particular, thermal PBE exhibits close agreement with path integral Monte Carlo (PIMC) reference data at negligible additional computational cost. This work demonstrates the practical utility of thermal PBE as an accurate semilocal functional for simulations in the warm dense regime.

Keywords: Density functional theory; Exchange-correlation functional; Materials science; Warm dense matter

Temperature dependence of the dynamic structure factor of the electron liquid via analytic continuation

Chuna, T. M. ; Boehme, M. ; Dornheim, T.

All results have been computed for the unpolarized UEG, i.e., with an equal number of spin-up and spin-down electrons $N^\uparrow=N^\downarrow=N

2$ for $N=34$. For $r_s = 20$ and at $\Theta=0.75$, there are 1000 independent MCMC seeds, at $\Theta=1, , 2$ there are $280$ seeds, at $\Theta=4, ,8$ there are $277$ seeds. To compute the data, we conduct leave-one-out binning across the seeds and for all the data, the variance of the mean is $\delta F \approx 10^{-3}-10^{-4}$. This error estimate is computed for each leave-one-out-bin via Hatano’s error formula~\cite{hatano1994data} and verified using leave-one-out binning~\cite{berg_book_2004}. This is the online repository with the PIMC results for $F(\mathbf{q},\tau)$ and analytic continuation results for $S(q,\omega)$ seen “Temperature dependence of the dynamic structure factor of the electron liquid via analytic continuation” article. The data contained here is (1) leave-one-binned imaginary time correlation functions F(tau) (units dimensionless) over tau (units 1

Hartree) and there error (2) the dynamic structure factors (units 1

Hartree) over omega (units Hartree) obtained using Bryan’s MEM with the static approximation as the Bayesian prior (3) the dynamic structure factors (units 1

Hartree) over omega (units Hartree) obtained using PyLIT with the static approximation as the Bayesian prior (4) The omega->0 limit of the ideal gas susceptibility chi(q,0)

beta (units dimensionless) over q (units 1

Keywords: analytic conitnuation; dynamic structure factor; uniform electron gas

Research data in the HZDR data repository RODARE Publication date: 2026-03-28 Open access DOI: 10.14278

Veröffentlichung im HZDR-Daten-Repository RODARE - Id 4579

Data publication: Taylor series perspective on ab initio path integral Monte Carlo simulations with Fermi-Dirac statistics

Dornheim, T. ; Benedix Robles, A. ; Hamann, P. ; Chuna, T. M. ; Svensson, P. ; Schwalbe, S. ; Moldabekov, Z. ; Tolias, P.; Vorberger, J.

This repository contains the PIMC raw data for the publication “Taylor series perspective on ab initio path integral Monte Carlo simulations with Fermi-Dirac statistics” using the same units and formatting as in the plots.

53fr-mnm6 references this (Id 43150) publication

Taylor series perspective on ab initio path integral Monte Carlo simulations … ROBIS: 41848 has used this (Id 43150) publication of HZDR-primary research data

Research data in the HZDR data repository RODARE Publication date: 2026-03-16 Open access DOI: 10.14278

Veröffentlichung im HZDR-Daten-Repository RODARE - Id 4562

Data publication: Reweighting scheme for the calculation of grand-canonical expectation values in quantum Monte Carlo simulations with a fermion sign problem

Hamann, P. ; Vorberger, J. ; Dornheim, T.

This repository contains all PIMC simulation data related to the publication: Reweighting scheme for the calculation of grand-canonical expectation values in quantum Monte Carlo simulations with a fermion sign problem

ctpp.70091 references this (Id 43088) publication

Reweighting scheme for the calculation of grand-canonical expectation values … ROBIS: 41824 has used this (Id 43088) publication of HZDR-primary research data

Research data in the HZDR data repository RODARE Publication date: 2026-03-04 Open access DOI: 10.14278

Veröffentlichung im HZDR-Daten-Repository RODARE - Id 4550

Direct path integral Monte Carlo approach to the free energy of warm dense matter

Matter under extreme densities, temperatures, and pressures is abundant throughout our universe and occurs in a variety of celestial objects such as giant planets, brown dwarfs, and the outer layer of neutron stars. On Earth, such warm dense matter (WDM) [1] plays an important role for cutting-edge technological applications such as material science and discovery. However, the holy grail of contemporary high energy density science is given by inertial confinement fusion, where both the fusion fuel and the ablator material have to traverse the WDM regime in a controlled way during the initial phase of the compression. Unfortunately, the rigorous theoretical description of WDM is notoriously difficult. Ab initio density functional theory (DFT) simulations have emerged as the workhorse in the field, but their accuracy decisively depends on the utilized exchange—correlation (XC) free energy functional, which has to be supplied as an external input. The gold standard is given by quasi-exact path integral Monte Carlo (PIMC) simulations, which are, in principle, capable of giving exact results for a great variety of material properties. Here, I will give an overview of recent developments in the direct PIMC estimation of the free energy [2,3]—the key quantity for thermal DFT simulations and equation-of-state tables. This includes novel technical developments to deal efficiently with the fermion sign problem [4,5], as well as new opportunities to directly estimate the chemical potential [6]. From a physics perspective, I will show recent results for the uniform electron gas as well as for warm dense hydrogen. Finally, I will give an outlook on upcoming developments and opportunities for improved equation-of-state tables and XC functionals. [1] J. Vorberger et al., Roadmap for warm dense matter physics, arXiv:2505.02494 [2] T. Dornheim et al. Phys. Rev. B 111, L041114 (2025) [3] T. Dornheim et al., Phys. Rev. Research 7, 023250 (2025) [4] T. Dornheim et al., J. Chem. Theory. Comput. 21, 7290–7303 (2025) [5] P. Svensson et al., J. Phys. Chem. Lett. 16, 10639–10646 (2025) [6] T. Dornheim et al., Phys. Rev. B 111, 115149 (2025)

Invited lecture (Conferences) Sanibel Symposium, 22.-27.02.2026, St Augustine Beach, Florida, USA

XFEL Imaging Techniques for High Energy Density and Inertial Fusion Energy Research at HED-HiBEF

Laso García, A. ; Mishchenko, M.; Bouffetier, V. ; Perez-Callejo, G.; Appel, K.; Arefiev, A.; Bähtz, C. ; Brambrink, E.; Cernaianu, M. O.; Doria, D.; Dornheim, T. ; Dyer, G. M.; Fefeu, N.; Galtier, E.; Gawne, T. D. ; Ghenuche, P.; Goede, S.; Hagemann, J.; Herbert, M.-L. ; Höppner, H. ; Huang, L. ; Humphries, O. S.; Jones, M.; Khaghani, D.; Kluge, T. ; Koliyadu, J.; Kraus, D. ; Ja Lee, H.; Lütgert, J.; Makita, M.; Naedler, J.-P.; Nagler, B.; Nakatsutsumi, M.; Nguyen, Q. L.; Pelka, A. ; Preston, T. R.; Bing Qu, C.; Rahul, S. V.; Randolph, L.; Redmer, R.; Rehwald, M. ; Rinderknecht, H. G.; Rodriguez-Fernandez, A.; Santos, J. J.; Schramm, U. ; Smid, M. ; Strohm, C.; Strucka, J.; Tang, M.; Vagovic, P.; Vescovi Pinochet, M. A. ; Yang, L. ; Zeil, K. ; Zastrau, U.; Cowan, T. ; Toncian, T.

The imaging platform developed at the High Energy Density - Helmholtz International Beamline for Extreme Fields (HED-HiBEF) instrument at the European XFEL and its applications to high energy density and fusion related research are presented. The platform combines the XFEL beam with the high-intensity short-pulse laser ReLaX and the high-energy nanosecond-pulse laser DiPOLE-100X. The spatial resolution is better than 500 nm and the temporal resolution of the order of 50 fs. The influence of the XFEL source in the x-ray imaging method is discussed. Free-propagation x-ray phase contrast imaging and Talbot-Lau imaging setups are shown. We show examples of blast waves and converging cylindrical shocks in aluminium, resonant absorption measurements of specific charged states in copper with ReLaX and planar shocks in polystyrene material generated by DiPOLE-100X. For the first time, we show the application of Talbot-Lau interferometry to convergent cyli