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Related papers: Linear density response function within the time-d…

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The van Leeuwen proof of linear-response time-dependent density functional theory (TDDFT) is generalized to thermal ensembles. This allows generalization to finite temperatures of the Gross-Kohn relation, the exchange-correlation kernel of…

Chemical Physics · Physics 2016-06-15 Aurora Pribram-Jones , Paul E. Grabowski , Kieron Burke

We formulate a rigorous method for calculating a nonadiabatic (frequency-dependent) exchange-correlation (XC) kernel required for correct description of both equilibrium and nonequilibrium properties of strongly correlated systems within…

Strongly Correlated Electrons · Physics 2014-10-13 Volodymyr Turkowski , Talat S. Rahman

We calculate the imaginary part of the frequency-dependent dielectric function of bulk silicon by applying time-dependent density-functional theory based on the exact-exchange (EXX) Kohn-Sham (KS) band structure and the adiabatic…

Materials Science · Physics 2016-01-01 Yong-Hoon Kim , Martin Staedele , Andreas Goerling

As part of a project to obtain better optical response functions for nano materials and other systems with strong excitonic effects we here calculate the exchange-correlation (XC) potential of density-functional theory (DFT) at a level of…

Other Condensed Matter · Physics 2009-11-13 M. Hellgren , U. von Barth

The exact exchange potential in time-dependent density-functional theory is defined as an orbital functional through the time-dependent optimized effective potential (TDOEP) method. We numerically solve the TDOEP integral equation for the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 H. O. Wijewardane , C. A. Ullrich

We develop a scheme for building the scalar exchange-correlation (xc) kernel of time-dependent density functional theory (TDDFT) from the tensorial kernel of time-dependent {\em current} density functional theory (TDCDFT) and the Kohn-Sham…

Materials Science · Physics 2009-11-13 V. U. Nazarov , J. M. Pitarke , Y. Takada , G. Vignale , Y. -C. Chang

Linear-response time-dependent density-functional theory (TDDFT) can describe excitonic features in the optical spectra of insulators and semiconductors, using exchange-correlation (xc) kernels behaving as $-1/k^{2}$ to leading order. We…

Materials Science · Physics 2021-08-18 Jiuyu Sun , Cheng-Wei Lee , Alina Kononov , André Schleife , Carsten A. Ullrich

A new parameter-free approximation for the exchange-correlation kernel $f_{\rm xc}$ of time-dependent density functional theory is proposed. This kernel is expressed as an algorithm in which the exact Dyson equation for the response as well…

Materials Science · Physics 2015-05-28 S. Sharma , J. K. Dewhurst , A. Sanna , E. K. U. Gross

Within the framework of ab initio time-dependent density-functional theory (TD-DFT), we propose a static approximation to the exchange-correlation kernel based on the jellium-with-gap model. This kernel accounts for electron-hole…

By exploiting freedoms in the definitions of 'correlation', 'exchange' and 'Hartree' physics in ensemble systems we better generalise the notion of 'exact exchange' (EXX) to systems with fractional occupations functions of the frontier…

Atomic Physics · Physics 2014-07-28 Tim Gould , John F. Dobson

Applying the novel exact-exchange (EXX) Kohn-Sham method within time-dependent density-functional theory, we obtained the optical absorption spectrum of bulk silicon in good agreement with experiments including excitonic features. Analysis…

Materials Science · Physics 2016-01-01 Yong-Hoon Kim , Andreas Goerling

We identify the key property that the exchange-correlation (XC) kernel of time-dependent density functional theory must have in order to describe long-range charge-transfer excitations. We show that the discontinuity of the XC potential as…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 M. Hellgren , E. K. U. Gross

To examine the applicability of the time-dependent density-functional theory (TDDFT) for treating the electron-nucleus coupling in excited states, we calculate the strength distribution associated with the pi-pi* transition in ethylene. The…

Chemical Physics · Physics 2007-05-23 G. F. Bertsch , J. Giansiracusa , K. Yabana

The electronic exchange-correlation (XC) kernel constitutes a fundamental input for the estimation of a gamut of material properties such as the dielectric characteristics, the thermal and electrical conductivity, or the response to an…

Computational Physics · Physics 2024-02-26 Zhandos A. Moldabekov , Maximilian Böhme , Jan Vorberger , David Blaschke , Tobias Dornheim

We obtain an exact solution of the time-dependent Schroedinger equation for a two-electron system confined to a plane by an isotropic parabolic potential whose curvature is periodically modulated in time. From this solution we compute the…

Condensed Matter · Physics 2009-10-31 Irene D'Amico , Giovanni Vignale

While the variational principle for excited-state energies leads to a route to obtaining excited-state densities from time-dependent density functional theory, relatively little attention has been paid to the quality of the resulting…

Chemical Physics · Physics 2025-09-12 Anna Baranova , Neepa T. Maitra

An approximate solution to the time-dependent density functional theory (TDDFT) response equations for finite systems is developed, yielding corrections to the single-pole approximation. These explain why allowed Kohn-Sham transition…

Materials Science · Physics 2009-11-07 H. Appel , E. K. U. Gross , K. Burke

The dynamical exchange-correlation kernel $f_{xc}$ of a non-uniform electron gas is an essential input for the time-dependent density functional theory of electronic systems. The long-wavelength behavior of this kernel is known to be of the…

Materials Science · Physics 2009-11-13 V. U. Nazarov , G. Vignale , Y. -C. Chang

An explicit expression for the quadratic density-response function of a many-electron system is obtained in the framework of the time-dependent density-functional theory, in terms of the linear and quadratic density-response functions of…

Materials Science · Physics 2009-11-10 V. U. Nazarov , J. M. Pitarke , C. S. Kim , Y. Takada

Linear response calculations based on the time-dependent density-functional theory are presented. Especially, we report results of the finite amplitude method which we have recently proposed as an alternative and feasible approach to the…