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.
...
ISBN
9789513976873Contains 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
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