A DFT+nonhomogeneous DMFT approach for finite systems

Kabir, Alamgir; Turkowski, Volodymyr; Rahman, Talat S.

doi:10.1088/0953-8984/27/12/125601

Cited by 2 publications

(1 citation statement)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 Interface of density functional and dynamical mean field theory for the simulation of complex structures Considerable efforts have been focussed on the modelling of correlated nanoscale systems using DMFT techniques, e.g., [5][6][7][8][9][10][11][12][13][14][15][16]. Here, we describe the approach to a material realistic DMFT scheme for nanosystems which has been implemented by the authors during the course of FOR 1346, and which is particularly flexible.…”

Section: Introductionmentioning

confidence: 99%

Realistic theory of electronic correlations in nanoscopic systems

Schüler

Barthel

Wehling

et al. 2017

Eur. Phys. J. Spec. Top.

View full text Add to dashboard Cite

Abstract.Nanostructures with open shell transition metal or molecular constituents host often strong electronic correlations and are highly sensitive to atomistic material details. This tutorial review discusses method developments and applications of theoretical approaches for the realistic description of the electronic and magnetic properties of nanostructures with correlated electrons. First, the implementation of a flexible interface between density functional theory and a variant of dynamical mean field theory (DMFT) highly suitable for the simulation of complex correlated structures is explained and illustrated. On the DMFT side, this interface is largely based on recent developments of quantum Monte Carlo and exact diagonalization techniques allowing for efficient descriptions of general four fermion Coulomb interactions, reduced symmetries and spin-orbit coupling, which are explained here. With the examples of the Cr (001) surfaces, magnetic adatoms, and molecular systems it is shown how the interplay of Hubbard U and Hund's J determines charge and spin fluctuations and how these interactions drive different sorts of correlation effects in nanosystems. Non-local interactions and correlations present a particular challenge for the theory of low dimensional systems. We present our method developments addressing these two challenges, i.e., advancements of the dynamical vertex approximation and a combination of the constrained random phase approximation with continuum medium theories. We demonstrate how non-local interaction and correlation phenomena are controlled not only by dimensionality but also by coupling to the environment which is typically important for determining the physics of nanosystems.a

show abstract

Section: Introductionmentioning

confidence: 99%

Realistic theory of electronic correlations in nanoscopic systems

Schüler

Barthel

Wehling

et al. 2017

Eur. Phys. J. Spec. Top.

View full text Add to dashboard Cite

show abstract

Density functional plus dynamical mean-field theory of the spin-crossover moleculeFe(phen)2(NCS)2

2015

View full text Add to dashboard Cite

We study the spin-crossover molecule Fe(phen)2(NCS)2 using density functional theory (DFT) plus dynamical mean-field theory, which allows access to observables not attainable with traditional quantum chemical or electronic structure methods. The temperature dependent magnetic susceptibility, electron addition and removal spectra, and total energies are calculated and compared to experiment. We demonstrate that the proper quantitative energy difference between the high-spin and low-spin state, as well as reasonably accurate values of the magnetic susceptibility can be obtained when using realistic interaction parameters. Comparisons to DFT and DFT+U calculations demonstrate that dynamical correlations are critical to the energetics of the low-spin state. Additionally, we elucidate the differences between DFT+U and spin density functional theory (SDFT) plus U methodologies, demonstrating that DFT+U can recover SDFT+U results for an appropriately chosen on-site exchange interaction.

show abstract

A DFT+nonhomogeneous DMFT approach for finite systems

Cited by 2 publications

References 35 publications

Realistic theory of electronic correlations in nanoscopic systems

Realistic theory of electronic correlations in nanoscopic systems

Density functional plus dynamical mean-field theory of the spin-crossover moleculeFe(phen)2(NCS)2

Contact Info

Product

Resources

About