X-ray-scattering determination of the dynamic structure factor of Al metal

Pm, Platzman; Isaacs, Ellen; Williams, Hugh; Zschack, P.; Ice, G. E.

doi:10.1103/physrevb.46.12943

Cited by 45 publications

(49 citation statements)

References 14 publications

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“…6 one can observe that the calculated loss function at large momentum transfers is dominated, except the weak peaks denoted by dashed and dotted lines, by a single high-energy broad peak. This observation suggests that lead might be a more suitable candidate than Be and Al for observation [67][68][69][70] at low energies of the multipair and excitonic effects which were previously discussed for simple metals [71].…”

Section: General Resultsmentioning

confidence: 88%

Effects of5delectrons and spin-orbit interaction on the characteristics of bulk plasmons in lead

2014

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An ab initio study of the dynamical dielectric response of bulk lead is presented. The influence of the 5d semicore states on the characteristics of the bulk plasmon is analyzed by means of first-principles pseudopotential calculations. The effects of spin-orbit interactions and local-fields are also studied in detail. The inclusion of the 5d semicore states in the valence configuration completely changes the high-energy-transfer dielectric properties of bulk Pb. In particular, it lowers the computed bulk plasmon energy by about 3.5 eV, bringing its frequency to good agreement with experimental data. In general, the high-energy-transfer dielectric response of bulk Pb is found to be shaped mostly by the interplay between the interband transitions involving the semicore 5d states and the spin-orbit coupling interaction. Local-field effects are found to affect the relative spectral weight of the high-energy excitations, while leaving their dispersion mostly unaffected.

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Section: General Resultsmentioning

confidence: 88%

Effects of5delectrons and spin-orbit interaction on the characteristics of bulk plasmons in lead

2014

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“…An additional example is provided by Ref. 24. There the authors point out a shoulder on the high frequency side of S(k,) for kϭ1.1 at Ϸ3.44 ͓see Fig.…”

Section: ͑44͒mentioning

confidence: 92%

Dynamical correlations in the electron gas

Sturm

Gusarov

2000

Phys. Rev. B

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Dynamical correlations in the homogeneous electron gas are a central issue in time-dependent density functional theory and are investigated here by evaluating exactly the leading corrections to the RPA proper polarizability. We obtain Im ⑀(k,) at arbitrary k and outside the ͑single͒ particle-hole excitation spectrum. We calculate the imaginary part of the local field factor Im G(k,) and compare Im ⑀(k,) with contributions arising from band structure effects in Al. These results are applied to Al to discuss their relative importance on plasmon damping and on the high frequency tail in the dynamical structure factor. Dynamical correlations mediated by the crystal potential contribute to the optical absorption of alkali metals below the onset of interband transitions.

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“…Dynamical structure factor S(q, ) ϭϪ2ប͐drdrЈe Ϫiq(rϪrЈ) Im (r,rЈ, ) of aluminum, calculations from Fleszar et al (1995). Open circles are experimental data from Platzman et al (1992). In the left panel, they are compared with the Kohn-Sham independent particle response (full line labeled S KS , obtained taking ϭ 0 in the above expression for S) (the double-bump structure was already obtained by Maddocks et al, 1994aMaddocks et al, , 1994b.…”

Section: Figmentioning

confidence: 99%

Electronic excitations: density-functional versus many-body Green’s-function approaches

2002

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Electronic excitations lie at the origin of most of the commonly measured spectra. However, the first-principles computation of excited states requires a larger effort than ground-state calculations, which can be very efficiently carried out within density-functional theory. On the other hand, two theoretical and computational tools have come to prominence for the description of electronic excitations. One of them, many-body perturbation theory, is based on a set of Green's-function equations, starting with a one-electron propagator and considering the electron-hole Green's function for the response. Key ingredients are the electron's self-energy ⌺ and the electron-hole interaction. A good approximation for ⌺ is obtained with Hedin's GW approach, using density-functional theory as a zero-order solution. First-principles GW calculations for real systems have been successfully carried out since the 1980s. Similarly, the electron-hole interaction is well described by the Bethe-Salpeter equation, via a functional derivative of ⌺. An alternative approach to calculating electronic excitations is the time-dependent density-functional theory (TDDFT), which offers the important practical advantage of a dependence on density rather than on multivariable Green's functions. This approach leads to a screening equation similar to the Bethe-Salpeter one, but with a two-point, rather than a four-point, interaction kernel. At present, the simple adiabatic local-density approximation has given promising results for finite systems, but has significant deficiencies in the description of absorption spectra in solids, leading to wrong excitation energies, the absence of bound excitonic states, and appreciable distortions of the spectral line shapes. The search for improved TDDFT potentials and kernels is hence a subject of increasing interest. It can be addressed within the framework of many-body perturbation theory: in fact, both the Green's functions and the TDDFT approaches profit from mutual insight. This review compares the theoretical and practical aspects of the two approaches and their specific numerical implementations, and presents an overview of accomplishments and work in progress. CONTENTS

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X-ray-scattering determination of the dynamic structure factor of Al metal

Cited by 45 publications

References 14 publications

Effects of5delectrons and spin-orbit interaction on the characteristics of bulk plasmons in lead

Effects of5delectrons and spin-orbit interaction on the characteristics of bulk plasmons in lead

Dynamical correlations in the electron gas

Electronic excitations: density-functional versus many-body Green’s-function approaches

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