---
title: "Helmholtz-Zentrum Dresden-Rossendorf researchers develop ab initio PIMC/DFT for warm dense matter at worldwide facilities; Fermion sign problem tackled by PREXTREME grant"
sdDatePublished: "2026-07-31T13:18:00Z"
source: "https://www.hzdr.de/db/Cms?pOid=78191\u0026pNid=0\u0026pLang=en"
topics:
  - name: "physics"
    identifier: "medtop:20000731"
  - name: "scientific research"
    identifier: "medtop:20000735"
  - name: "nuclear physics"
    identifier: "medtop:20000733"
locations:
  - "Dresden"
---


Helmholtz-Zentrum Dresden-Rossendorf researchers develop ab initio PIMC/DFT for warm dense matter at worldwide facilities; Fermion sign problem tackled by PREXTREME grant

About FWKH - Helmholtz-Zentrum Dresden-Rossendorf, HZDR

We work on both the theoretical and experimental aspects of high energy density (HED) science, with a particular focus on warm dense matter (WDM).

Ab-initio simulations: we develop state-of-the-art path integral Monte Carlo (PIMC) and density functional theory (DFT) simulations to describe extreme states of matter. This includes the exploration of thermal XC-effects (DFT) and of the fermion sign problem (PIMC).

Time-dependent DFT: we develop and apply novel TD-DFT methodologies for the calculation of spectral properties, in particular related to x-ray Thomson scattering (XRTS).

X-ray Thomson scattering: we develop integrated modeling capabilities [xDave¹, HEART²] and model-free analysis techniques for XRTS experiments, and participate in experiments at facilities world wide [EurXFEL, LCLS, SACLA, NIF, …]

Analytic continuation: we develop novel methods [PyLIT³] for the computation of dynamic

spectral properties from quasi-exact PIMC simulation results in the imaginary-time domain.

Density response theory: we develop novel concepts for the calculation of linear and non-linear density response properties of quantum many-body systems, with a particular focus on warm dense matter

X-ray absorption and emission spectroscopy: we work on x-ray absorption

emission experiments to study the ultrafast heating and ionization dynamics in hot dense matter

ERC Starting Grant “Predicting the Extreme” (PREXTREME): we develop new ways to deal with the notorious fermion sign problem in ab initio path integral Monte Carlo simulations of warm dense matter (and other quantum degenerate Fermi systems).

DFG Heisenberg Project DO 2670

1-1: we utilize our unique combination of cutting-edge PIMC, DFT and XRTS capabilities to pursue a fundamentally improved description of warm dense matter.

EruM Data Project “DEMOS: Demokratisierung von Modellen”:

BMFTR Project “VANLIFE”: we contribute ab-initio results for the equation-of-state of light elements for inertial fusion energy applications.