Applying the Liouville-Lanczos Method of Time-Dependent Density-Functional Theory to Warm Dense Matter

• DOI: 10.48550/arxiv.2502.04921
• Publication Date: 2025-02-07
• Authors: Zhandos A. Moldab...; Sebastian Schwalbe; Thomas Gawne; Thomas R. Preston; Jan Vorberger; Tobias Dornheim
• Keywords: Plasma Physics (physics.plasm-ph); Chemical Physics (physics.chem-ph); Physics - Chemical Physics; FOS: Physical sciences; Computational Physics (physics.comp-ph); Physics - Computational Physics; Physics - Plasma Physics

Ab initio modeling of dynamic structure factors (DSF) and related density response properties in the warm dense matter (WDM) regime is a challenging computational task. The DSF, convolved with probing X-ray beam instrument function, measured Thomson scattering (XRTS) experiments, which allows for study electronic at microscopic level. Among various ab methods, linear time-dependent functional theory (LR-TDDFT) key framework simulating DSF. standard approach LR-TDDFT computing DSF relies on orbital representation. A significant drawback this method unfavorable scaling number required empty bands as wavenumber increases, making impractical XRTS measurements over large energy scales, such backward geometry. We consider test an alternative that employs Liouville-Lanczos (LL) This does not require states momentum transfer values broad frequency range to be accessed. compare results obtained from LL those within projector augmented-wave formalism isochorically heated aluminum hydrogen. Additionally, we utilize exact path integral Monte Carlo (PIMC) imaginary-time density-density correlation function (ITCF) hydrogen rigorously benchmark approach. discuss application calculating DSFs ITCFs different wavenumbers, effects pseudopotentials, role Lorentzian smearing. successful validation under WDM conditions makes it valuable addition simulation landscape, supporting experimental efforts advancing theory.