scholarly journals Relativistic density-functional theory based on effective quantum electrodynamics

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Julien Toulouse
Keyword(s):  
Density Functional Theory ◽  
Quantum Electrodynamics ◽  
Density Functional ◽  
Degrees Of Freedom ◽  
Fock Space ◽  
Particle Interaction ◽  
Functional Theory ◽  
Electron Positron ◽  
Molecular Calculations ◽  
Coordinate Scaling

A relativistic density-functional theory based on a Fock-space effective quantum-electrodynamics (QED) Hamiltonian using the Coulomb or Coulomb-Breit two-particle interaction is developed. This effective QED theory properly includes the effects of vacuum polarization through the creation of electron-positron pairs but does not include explicitly the photon degrees of freedom. It is thus a more tractable alternative to full QED for atomic and molecular calculations. Using the constrained-search formalism, a Kohn-Sham scheme is formulated in a quite similar way to non-relativistic density-functional theory, and some exact properties of the involved density functionals are studied, namely charge-conjugation symmetry and uniform coordinate scaling. The usual no-pair Kohn-Sham scheme is obtained as a well-defined approximation to this relativistic density-functional theory.

scholarly journals Macroscopic quantum electrodynamics and density functional theory approaches to dispersion interactions between fullerenes

2020 ◽  
Vol 22 (40) ◽  
pp. 23295-23306
Author(s):  
Saunak Das ◽  
Johannes Fiedler ◽  
Oliver Stauffert ◽  
Michael Walter ◽  
Stefan Yoshi Buhmann ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Excited States ◽  
Quantum Electrodynamics ◽  
Density Functional ◽  
Dispersion Interactions ◽  
Functional Theory ◽  
Electronically Excited States ◽  
Macroscopic Quantum ◽  
Td Dft ◽  
Electronically Excited

Van der Waals potentials determine supramolecular structures of molecules in ground and long-lived electronically excited states. We investigate how macroscopic quantum electrodynamics can be used to efficiently describe such potentials based on (TD)DFT-derived polarizabilities.

Electron-positron density-functional theory

1986 ◽  
Vol 34 (6) ◽  
pp. 3820-3831 ◽  
Author(s):  
E. Boroński ◽  
R. M. Nieminen
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Electron Positron

SPIN DENSITIES AND CURRENTS IN THE ROUTHIAN APPROXIMATION

2006 ◽  
Vol 15 (02) ◽  
pp. 553-559
Author(s):  
JOHANN BARTEL ◽  
KAMEL BENCHEIKH ◽  
PHILIPPE QUENTIN
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Degrees Of Freedom ◽  
Vector Fields ◽  
Semiclassical Approximation ◽  
Spin Current ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Current Densities ◽  
Spin Densities

The structure of spin densities and the associated spin-current densities, induced by the coupling of external vector fields to the orbital and spin degrees of freedom, is studied within the framework of the Extended Thomas-Fermi method, a semiclassical version of the density-functional theory. A special emphasis is put on the rotational case where our approach amounts to perform a semiclassical approximation of the so-called generalized Routhian approach.

scholarly journals Coordinate Scaling in Time-Independent Excited-State Density Functional Theory for Coulomb Systems

Computation ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 59
Author(s):  
Ágnes Nagy
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Excited States ◽  
Density Functional ◽  
Coulomb Systems ◽  
State Theory ◽  
State Density ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Coordinate Scaling

A time-independent density functional theory for excited states of Coulomb systems has recently been proposed in a series of papers. It has been revealed that the Coulomb density determines not only its Hamiltonian, but the degree of excitation as well. A universal functional valid for any excited state has been constructed. The excited-state Kohn–Sham equations bear resemblance to those of the ground-state theory. In this paper, it is studied how the excited-state functionals behave under coordinate scaling. A few relations for the scaled exchange, correlation, exchange-correlation, and kinetic functionals are presented. These relations are expected to be advantageous for designing approximate functionals.

First-Principles Study on Positron States at Li-Adsorbed Al(100) Surfaces: Effect of Electron-Positron Correlation

2017 ◽  
Vol 373 ◽  
pp. 46-49 ◽  
Author(s):  
Satoshi Hagiwara ◽  
Yasumitsu Suzuki ◽  
Kazuyuki Watanabe
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Generalized Gradient ◽  
Local Electron ◽  
Functional Theory ◽  
Positron States ◽  
Generalized Gradient Approximation ◽  
Electron Positron ◽  
Two Component

We investigated positron states at Li-adsorbed Al(100) surfaces using \textit{ab-initio} two-component density functional theory. The results thus obtained by using semi-local electron-positron (e-p) correlation functionals with the generalized gradient approximation well reproduce the experimental results, showing that reliable e-p correlation functionals are needed to properly describe the various properties of positron surface state.

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