Calculations of single particle spectra in density functional theory

The superdeformed rotational band in [Formula: see text]Ca is studied with the cranking covariant density functional theory complemented by a shell-model-like approach for treating the pairing correlations. The microscopic and self-consistent description of the superdeformed rotational band is obtained. The calculated energy surfaces show local minimums at [Formula: see text] from rotational frequency [Formula: see text] [Formula: see text] to [Formula: see text][Formula: see text]MeV. The shape coexistence of spherical, normal deformation and superdeformation is found at [Formula: see text][Formula: see text]MeV. The single-particle levels and configurations are analyzed in details with the deformation. The configuration of the superdeformed band is figured out as [Formula: see text]. The single-particle Routhians indicate that the neutrons configuration plays a key role in the formation of the superdeformed band, and the change of the protons configuration at [Formula: see text][Formula: see text]MeV terminates the superdeformed band. The importance of pairing correlation to the superdeformed band is also studied in terms of the moments of inertia and the angular momentum.

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Density Functional Theory of Normal and Superconducting Electron Liquids: Explicit Functionals via the Gradient Expansion

Australian Journal of Physics ◽

10.1071/ph960103 ◽

1996 ◽

Vol 49 (1) ◽

pp. 103 ◽

Cited By ~ 6

Author(s):

CA Ullrich ◽

EKU Gross

Keyword(s):

Density Functional Theory ◽

Single Particle ◽

Density Functional ◽

Particle System ◽

Variational Equation ◽

State Theory ◽

Functional Theory ◽

Gradient Expansion ◽

Particle Potential ◽

Single Particle Potential

The basic idea of density functional theory is to map an interacting many-particle system on an effective non-interacting system in such a way that the ground-state densities of the two systems are identical. The non-interacting particles move in an effective local potential which is a functional of the density. The central task of density functional theory is to find good approximations for the density dependence of this local single-particle potential. An overview of recent advances in the construction of this potential (beyond the local-density approximation) will be given along with successful applications in quantum chemistry and solid state theory. We then turn to the extension of density functional theory to superconductors and first discuss the Hohenberg-Kohn-Sham-type existence theorems. In the superconducting analogue of the the normal-state Kohn-Sham formalism, a local single-particle potential is needed which now depends on two densities, the ordinary density n(r) and the anomalous density △(r,r/). As a first step towards the construction of such a potential, a gradient expansion technique for superconductors is presented and applied to calculate an approximation of the non-interacting kinetic energy functional Ts[n, △]. We also obtain a Thomas-Fermi-type variational equation for superconductors.

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Quasiparticle band structure and density-functional theory: Single-particle excitations and band gaps in lattice models

Physical Review B ◽

10.1103/physrevb.59.15617 ◽

1999 ◽

Vol 59 (24) ◽

pp. 15617-15624 ◽

Cited By ~ 11

Author(s):

D. W. Hess ◽

J. W. Serene

Keyword(s):

Density Functional Theory ◽

Band Structure ◽

Single Particle ◽

Density Functional ◽

Lattice Models ◽

Band Gaps ◽

Functional Theory ◽

Quasiparticle Band

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Density functional theory for collisionless plasmas – equivalence of fluid and kinetic approaches

Journal of Plasma Physics ◽

10.1017/s0022377820000240 ◽

2020 ◽

Vol 86 (2) ◽

Cited By ~ 1

Author(s):

Giovanni Manfredi

Keyword(s):

Density Functional Theory ◽

Single Particle ◽

Density Functional ◽

Particle Density ◽

Body Wave ◽

Collisionless Plasma ◽

Memory Storage ◽

Closure Relation ◽

Functional Theory ◽

Single Particle Density

Density functional theory (DFT) is a powerful theoretical tool widely used in such diverse fields as computational condensed-matter physics, atomic physics and quantum chemistry. DFT establishes that a system of $N$ interacting electrons can be described uniquely by its single-particle density $n(\boldsymbol{r})$ , instead of the $N$ -body wave function, yielding an enormous gain in terms of computational speed and memory storage space. Here, we use time-dependent DFT to show that a classical collisionless plasma can always, in principle, be described by a set of fluid equations for the single-particle density and current. The results of DFT guarantee that an exact closure relation, fully reproducing the Vlasov dynamics, necessarily exists, although it may be complicated (non-local in space and time, for instance) and difficult to obtain in practice. This goes against the common wisdom in plasma physics that the Vlasov and fluid descriptions are mutually incompatible, with the latter inevitably missing some ‘purely kinetic’ effects.

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