Timedependent densityfunctional theory for strongly correlated electrons
One of the most used methods in condensed matter theory and quantum chemistry for the description
of matter properties is Timedependent densityfunctional theory (TDDFT), an alternative formalism
to wave function methods which uses the timedependent electronic density for the determination of
any quantum average of an electronic system. The usual approach in TDDFT is by means a noninteracting
system, where all the interaction e ects are encoded in an e ective onebody potential
that exactly reproduces the timedependent density of any interacting system. The e ective potential
is called the exchangecorrelation (xc) potential. For the calculation of the excited states in TDDFT,
one needs the knowledge of the xc potential and its functional derivative with respect to the density,
which is known as the xc kernel. For practical applications, both the xc potential and the xc kernel
needs to be approximated. In the last years, better approximations for the xc potential and kernel have
been constructed, but it turns out that the usual approximations fail for the description of strongly
correlated systems. Recently, a new type of density functionals, the strictly correlated electrons (SCE)
formalism [1 3] have been constructed with the aim to describe the physics of strongly correlated
systems, but not tested so far for the obtaining of excitation energies. One way to gain insight and
test the performance of the density functionals is to compare them against exact expressions obtained
from exactly solvable systems. In this work, we construct such strongly correlated systems, and we
solve them exactly for the subsequent comparison with the predictions provided by the SCE density
functionals. The comparison of the results, therefore, will provide insights of the applicability of this
kind of density functionals, establishing in this way its range of validity.
...
Publisher
Jyväskylän yliopistoISBN
9789513976873ISSN Search the Publication Forum
24899003Contains publications
 Artikkeli I: Cort Barrada, L., Karlsson, D., Lani, G., & van Leeuwen, R. (2017). Timedependent densityfunctional theory for strongly interacting electrons. Physical Review A, 95 (4), 042505. DOI: 10.1103/PhysRevA.95.042505
 Artikkeli II: Cort Barrada, L., Nielsen, S. E. B., & van Leeuwen, R. (2019). Strictlycorrelatedelectron approach to excitation energies of dissociating molecules. Physical Review A, 99 (2), 022501. DOI: 10.1103/PhysRevA.99.022501
Metadata
Show full item recordCollections
 JYU Dissertations [806]
 Väitöskirjat [3498]
License
Related items
Showing items with similar title or keywords.

Timedependent densityfunctional theory for strongly interacting electrons
Cort Barrada, Luis; Karlsson, Daniel; Lani, Giovanna; van Leeuwen, Robert (American Physical Society, 2017)We consider an analytically solvable model of two interacting electrons that allows for the calculation of the exact exchangecorrelation kernel of timedependent density functional theory. This kernel, as well as ... 
Existence, uniqueness, and construction of the densitypotential mapping in timedependent densityfunctional theory
Ruggenthaler, Michael; Penz, Markus; van Leeuwen, Robert (Institute of Physics Publishing Ltd.; Institute of Physics, 2015)In this work we review the mapping from densities to potentials in quantum mechanics, which is the basic building block of timedependent densityfunctional theory and the Kohn–Sham construction. We first present detailed ... 
Merging Features from Green's Functions and Time Dependent Density Functional Theory : A Route to the Description of Correlated Materials out of Equilibrium?
Hopjan, M.; Karlsson, Daniel; Ydman, S.; Verdozzi, C.; Almbladh, C.O. (American Physical Society, 2016)We propose a description of nonequilibrium systems via a simple protocol that combines exchangecorrelation potentials from density functional theory with selfenergies of manybody perturbation theory. The approach, aimed ... 
KohnSham Decomposition in RealTime TimeDependent DensityFunctional Theory : An Efficient Tool for Analyzing Plasmonic Excitations
Rossi, Tuomas P.; Kuisma, Mikael; Puska, Martti J.; Nieminen, Risto M.; Erhart, Paul (American Chemical Society, 2017)Electronic excitations can be efficiently analyzed in terms of the underlying KohnSham (KS) electronhole transitions. While such a decomposition is readily available in the linearresponse timedependent densityfunctional ... 
Computational modelling of boron nitride nanostructures based on densityfunctional tightbinding
Nokelainen, Johannes (2014)Boorinitridin (BN) nanorakenteet ovat sekä rakenteellisesti että lujuusominaisuuksiensa puolesta hyvin samankaltaisia vastaavien hiilirakenteiden kanssa. Suurimpana erona on BN:n sähköinen eristävyys kun taas hiilirakenteet ...