<i>Ab initio</i>simulations of the dynamic ion structure factor of warm dense lithium

Witte, B. B. L.; Shihab, Mohammed; Glenzer, S. H.; Redmer, R.

doi:10.1103/physrevb.95.144105

Cited by 28 publications

(17 citation statements)

References 75 publications

(98 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The isochoric conductivities σ ic at a density of ρ=0.542 g/cm 3 , i.e., r ws = 3.251, are given for a range of T , while one value at ρ=0.6 g/cm 3 and T e = T i =4.5 eV, is also given. This is for conditions reported by Witte et al [41]. The experimental isobaric data from Oak Ridge [17] for σ ib (0.5 g/cm 3 at 0.05 eV to 0.4 g/cm 3 at 0.1378 eV), as well as the NPA σ ib , are also shown.…”

Section: The Conductivities Of Wdm Lithiummentioning

confidence: 88%

“…The conductivity of Li, at density ρ = 0.6 g/cm 3 at 4.5 eV estimated by Witte et al [41], is roughly a factor of five less than that obtained from NPA+Ziman. While the NPA calculation may differ from another calculation by, at worst, a factor of 2, it is hard to find an explanation for this strong disaccord, given the good agreement in the XRTS calculation.…”

Section: The Kubo-greenwood Conductivitymentioning

confidence: 91%

“…8) to compare our NPA results with the results from the DFT+MD simulations by Witte et al (Ref. [41], Fig.8). This establishes the excellent agreement with the electronic structure part of the NPA calculation and the ionic part, S ii (k), resulting from the DFT+MD calculations, irrespective of the exchange-correlation (XC) functional used.…”

Section: Appendixmentioning

confidence: 99%

See 2 more Smart Citations

Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime

et al. 2017

View full text Add to dashboard Cite

We study the conductivities σ of (i) the equilibrium isochoric state (σis), (ii) the equilibrium isobaric state (σ ib ), and also the (iii) non-equilibrium ultrafast matter (UFM) state (σ uf ) with the ion temperature Ti less than the the electron temperature Te. Aluminum, lithium and carbon are considered, being increasingly complex warm dense matter (WDM) systems, with carbon having transient covalent bonds. First-principles calculations, i.e., neutral-pseudoatom (NPA) calculations and density-functional theory (DFT) with molecular-dynamics (MD) simulations, are compared where possible with experimental data to characterize σic, σ ib and σ uf . The NPA σ ib are closest to the available experimental data when compared to results from DFT+MD, where simulations of about 64-125 atoms are typically used. The published conductivities for Li are reviewed and the value at a temperature of 4.5 eV is examined using supporting X-ray Thomson scattering calculations. A physical picture of the variations of σ with temperature and density applicable to these materials is given. The insensitivity of σ to Te below 10 eV for carbon, compared to Al and Li, is clarified.

show abstract

Section: The Conductivities Of Wdm Lithiummentioning

confidence: 88%

Section: The Kubo-greenwood Conductivitymentioning

confidence: 91%

See 1 more Smart Citation

Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Alternatively, quantum molecular dynamics (QMD) simulations can be used which treat the nuclei classically and the electrons quantum mechanically within finite‐temperature density‐functional theory (DFT). Although they have proven to be a versatile tool for calculating the equation of state, optical, and transport properties of WHDM, QMD simulations are computationally demanding so that simpler methods are still appropriate.…”

Section: Introductionmentioning

confidence: 99%

Ionization dynamics of dense matter generated by intense ultrashort X‐ray pulses

Shihab

Bornath

Redmer

2019

Contributions to Plasma Physics

View full text Add to dashboard Cite

We investigate a pump‐probe X‐ray Thomson scattering (XRTS) experiment that might be carried out at a free electron laser facility to study warm‐to‐hot states of dense matter. Ultrashort and intense X‐ray pulses with different energies (1,560–1,830 eV) heat a 1 µm thick Al target isochorically and create homogeneous and uncompressed warm‐to‐hot states of dense matter. A second pulse with variable delay probes this heated state via XRTS. The X‐ray laser–target interaction is modelled within radiation‐hydrodynamic simulations applying the HELIOS‐CR code. The HELIOS‐CR results qualitatively agree with Monte‐Carlo simulations, where the laser pulse absorption is simulated based on a uniform random sequence of events. The electron feature in the simultaneously observed X‐ray scattering spectrum is a function of the degree of ionization and the target temperature. Therefore, the temporal evolution of the plasmon peak measures the ionization dynamics on ultra‐short time scales. The XRTS spectrum is calculated based on the Chihara formula utilizing the Born‐Mermin approximation for the free electron dynamic structure factor. The proposed experiment will reveal important details of the ionization dynamics on ultra‐short time scales as well as of the relaxation on ps time scales.

show abstract

“…2requires careful convergence tests with respect to, e.g., particle number N , k-point grids, energy cutoff E c , and a proper adjustment of the delta function broadening parameter [37] in order to perform the extrapolation to the dc value. Such tests were carefully made in all calculations presented in [4,7,38]. DWD finds larger dc conductivities from NPA-Ziman calculations compared to DFT and attributes this partly to the "inability of the DFT-MD-KG approach to access small-k scattering contributions unless the number of atoms N in the simulation is sufficiently large."…”

mentioning

confidence: 99%

Comment on “Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime”

et al. 2019

Self Cite

View full text Add to dashboard Cite

Dharma-wardana et al. [M. W. C. Dharma-wardana et al., Phys. Rev. E 96, 053206 (2017)] recently calculated dynamic electrical conductivities for warm dense matter as well as for nonequilibrium two-temperature states termed "ultrafast matter" (UFM) [M. W. C. Dharma-wardana, Phys. Rev. E 93, 063205 (2016)]. In this comment we present two evident reasons, why these UFM calculations are neither suited to calculate dynamic conductivities nor x-ray Thomson scattering spectra in isochorically heated warm dense aluminum. First, the ion-ion structure factor, a major input into the conductivity and scattering spectra calculations, deviates strongly from that of isochorically heated aluminum. Second, the dynamic conductivity does not show a non-Drude behavior which is an essential prerequisite for a correct description of the absorption behavior in aluminum. Additionally, we clarify misinterpretations by Dharma-wardana et al. concerning the conductivity measurements of Gathers [

show abstract

Ab initiosimulations of the dynamic ion structure factor of warm dense lithium

Cited by 28 publications

References 75 publications

Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime

Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime

Ionization dynamics of dense matter generated by intense ultrashort X‐ray pulses

Comment on “Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime”

Contact Info

Product

Resources

About