The elastic feature of x-ray scattering from warm dense aluminum has recently been measured by Fletcher et al. [Nature Photonics 9, 274 (2015)]10.1038/nphoton.2015.41 with much higher accuracy than had hitherto been possible. This measurement is a direct test of the ionic structure predicted by models of warm dense matter. We use the method of pseudoatom molecular dynamics to predict this elastic feature for warm dense aluminum with temperatures of 1-100 eV and densities of 2.7-8.1g/cm^{3}. We compare these predictions to experiments, finding good agreement with Fletcher et al. and corroborating the discrepancy found in analyses of an earlier experiment of Ma et al. [Phys. Rev. Lett. 110, 065001 (2013)]PRLTAO0031-900710.1103/PhysRevLett.110.065001. We also evaluate the validity of the Thomas-Fermi model of the electrons and of the hypernetted chain approximation in computing the elastic feature and find them both wanting in the regime currently probed by experiments.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevE.92.033101 | DOI Listing |
J Chem Phys
January 2025
Moscow Center for Advanced Studies, Moscow, Russia.
The properties of the hydrogen fluid at high pressures are still of interest to the scientific community. The experimentally unreachable dynamical properties could provide new insights into this field. In 2020 [Cheng et al.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
Exact exchange contributions included in density functional theory calculations have rendered excellent electronic structure results on both cold and extremely hot matter. In this work, we develop a mixed deterministic-stochastic resolution-of-the-identity compressed exchange (mRICE) method for efficient calculation of exact and hybrid electron exchange, suitable for applications alongside mixed stochastic-deterministic density functional theory. mRICE offers accurate calculations of the electronic structure at a largely reduced computation time compared to other compression algorithms, such as Lin's adaptive compressed exchange, for the warm dense matter.
View Article and Find Full Text PDFPhys Rev E
November 2024
Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom.
We present two methods for computing the dynamic structure factor for warm dense hydrogen without invoking either the Born-Oppenheimer approximation or the Chihara decomposition, by employing a wave-packet description that resolves the electron dynamics during ion evolution. First, a semiclassical method is discussed, which is corrected based on known quantum constraints, and second, a direct computation of the density response function within the molecular dynamics. The wave-packet models are compared to PIMC and DFT-MD for the static and low-frequency behavior.
View Article and Find Full Text PDFRev Sci Instrum
October 2024
CEA, DAM, DIF, F-91297 Arpajon, France.
A pulsed power facility has been designed for studying the warm dense matter regime. It is based on the pulsed Joule heating technique, originally proposed by Korobenko and Rakhel [Int. J.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!