Orbital-Free Density-Functional Theory Simulations of the Dynamic Structure Factor of Warm Dense Aluminum

White, T. G.; Richardson, S. W.; Crowley, B.J.B.; Pattison, L. K.; Harris, Julie A.; Gregori, G.

doi:10.1103/physrevlett.111.175002

Cited by 85 publications

(73 citation statements)

References 41 publications

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“…(1), the ion feature. The electron motion in this term is dominated by the ion dynamics, e.g., ion acoustic waves [26,27], which are, however, not resolved in the considered experiments [3,14]. Hence we can approximate the dynamic ion-ion structure factor as S ii ( k,ω) = S ii ( k)δ(ω), thereby introducing the static ion feature as…”

Section: Theorymentioning

confidence: 98%

Ab initiocalculation of the ion feature in x-ray Thomson scattering

et al. 2015

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The spectrum of x-ray Thomson scattering is proportional to the dynamic structure factor. An important contribution is the ion feature which describes elastic scattering of x rays off electrons. We apply an ab initio method for the calculation of the form factor of bound electrons, the slope of the screening cloud of free electrons, and the ion-ion structure factor in warm dense beryllium. With the presented method we can calculate the ion feature from first principles. These results will facilitate a better understanding of x-ray scattering in warm dense matter and an accurate measurement of ion temperatures which would allow determining nonequilibrium conditions, e.g., along shock propagation.

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Section: Theorymentioning

confidence: 98%

Ab initiocalculation of the ion feature in x-ray Thomson scattering

et al. 2015

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“…Then physical observables such as the equation of state (pressure, internal energy), pair distribution functions, and diffusion coefficients can be extracted. In this way, the ion dynamics is treated properly, allowing one to resolve even the collective ion acoustic modes [48,49]. Furthermore, an evaluation of the Kubo formula is possible for a number of snapshots of the DFT-MD simulation; for details, see Refs.…”

Section: The Kubo-greenwood Formula: Dft-md Calculations Of Correlmentioning

confidence: 99%

Conductivity of warm dense matter including electron-electron collisions

et al. 2015

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We present an approach that can resolve the controversy with respect to the role of electron-electron collisions in calculating the dynamic conductivity of dense plasmas. In particular, the dc conductivity is analyzed in the low-density, nondegenerate limit where the Spitzer theory is valid and electron-electron collisions lead to the well-known reduction in comparison to the result considering only electron-ion collisions (Lorentz model). With increasing degeneracy, the contribution of electron-electron collisions to the dc conductivity is decreasing and can be neglected for the liquid metal domain where the Ziman theory is applicable. We give expressions for the effect of electron-electron collisions in calculating the conductivity in the warm dense matter region, i.e., for strongly coupled Coulomb systems at arbitrary degeneracy.

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“…7 OFDFT simulations with pseudopotentials have been applied successfully to the study, for example, of the fracture propagation in bulk aluminum or the structure factor of warm dense matter. 8 As a generalization of pseudopotentials and the linearaugmented-plane wave method the projector-augmented wave (PAW) method has been proposed as a method that allows the calculation of all-electron values with high accuracy and efficiency. 9 An all-electron method, refers to methods that solve the Schrödinger equation for an electronic system directly in the presence of the 1/r non-modified nuclear potential and all-electron values are those values that would be obtained with all-electron methods.…”

Section: Introductionmentioning

confidence: 99%

Orbital-free density functional theory implementation with the projector augmented-wave method

Lehtomäki

Makkonen

Miguel

et al. 2014

The Journal of Chemical Physics

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Laplacian-dependent models of the kinetic energy density: Applications in subsystem density functional theory with meta-generalized gradient approximation functionals The Journal of Chemical Physics 146, 064105 (2017) Orbital-free density functional theory implementation with the projector augmented-wave method We present a computational scheme for orbital-free density functional theory (OFDFT) that simultaneously provides access to all-electron values and preserves the OFDFT linear scaling as a function of the system size. Using the projector augmented-wave method (PAW) in combination with real-space methods, we overcome some obstacles faced by other available implementation schemes. Specifically, the advantages of using the PAW method are twofold. First, PAW reproduces all-electron values offering freedom in adjusting the convergence parameters and the atomic setups allow tuning the numerical accuracy per element. Second, PAW can provide a solution to some of the convergence problems exhibited in other OFDFT implementations based on Kohn-Sham (KS) codes. Using PAW and real-space methods, our orbital-free results agree with the reference all-electron values with a mean absolute error of 10 meV and the number of iterations required by the self-consistent cycle is comparable to the KS method. The comparison of all-electron and pseudopotential bulk modulus and lattice constant reveal an enormous difference, demonstrating that in order to assess the performance of OFDFT functionals it is necessary to use implementations that obtain all-electron values.

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Orbital-Free Density-Functional Theory Simulations of the Dynamic Structure Factor of Warm Dense Aluminum

Cited by 85 publications

References 41 publications

Ab initiocalculation of the ion feature in x-ray Thomson scattering

Ab initiocalculation of the ion feature in x-ray Thomson scattering

Conductivity of warm dense matter including electron-electron collisions

Orbital-free density functional theory implementation with the projector augmented-wave method

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