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Related papers: Beyond quasi-particle self-consistent $GW$ for mol…

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While the well-established $GW$ approximation corresponds to a resummation of the direct ring diagrams and is particularly well suited for weakly-correlated systems, the $T$-matrix approximation does sum ladder diagrams up to infinity and…

Chemical Physics · Physics 2022-04-28 Pierre-François Loos , Pina Romaniello

A one-dimensional quantum wire of Fermions is considered and ground state properties are calculated in the high density regime within the extended quasiparticle picture and Born approximation. Expanding the two-particle Green functions…

Strongly Correlated Electrons · Physics 2025-02-18 Klaus Morawetz , Vinod Ashokan , Kare Narain Pathak , Neil Drummond , Gianaurelio Cuniberti

To study the characteristic features of relativistic bound systems, the Bethe-Salpeter equation (BSE) for two equal mass spin 1/2 particles (like the deuteron) is solved in the cm-frame for a covariant separable interaction kernel. For that…

Nuclear Theory · Physics 2007-05-23 Frieder Kleefeld , Manfred Dillig

The GW approximation of many-body perturbation theory is an accurate method for computing electron addition and removal energies of molecules and solids. In a canonical implementation, however, its computational cost is $O(N^4)$ in the…

Chemical Physics · Physics 2021-04-21 Jan Wilhelm , Dorothea Golze , Leopold Talirz , Jürg Hutter , Carlo A. Pignedoli

The GW approximation within many-body perturbation theory is the state of the art for computing quasiparticle energies in solids. Typically, Kohn-Sham (KS) eigenvalues and eigenfunctions, obtained from a Density Functional Theory (DFT)…

The band structure of $\beta$-LiGaO$_2$ is calculated using the quasiparticle self-consistent QS$G\hat W$ method where the screened Coulomb interaction $\hat W$ is evaluated including electron-hole interaction ladder diagrams and $G$ is the…

Materials Science · Physics 2023-04-26 Niloufar Dadkhah , Walter R. L. Lambrecht , Dimitar Pashov , Mark van Schilfgaarde

On the basis of the self-consistent calculation scheme for the electron self-energy with the use of the three-point vertex function always satisfying the Ward identity, we find that the obtained quasiparticle dispersion in the normal state…

Superconductivity · Physics 2016-01-12 Yasutami Takada

The Bethe-Salpeter equation (BSE) can provide an accurate description of low-energy optical spectra of insulating crystals - even when excitonic effects are important. However, due to high computational costs it is only possible to include…

We use an all-electron implementation of the GW approximation to analyze several possible sources of error in the theory and its implementation. Among these are convergence in the polarization and Green's functions, the dependence of QP…

Materials Science · Physics 2013-05-29 M. van Schilfgaarde , T. Kotani , S. Faleev

We calculate groundstate total energies and single-particle excitation energies of seven pi conjugated molecules described with the semi-empirical Pariser-Parr-Pople (PPP) model using self-consistent many-body perturbation theory at the GW…

Mesoscale and Nanoscale Physics · Physics 2013-11-22 K. Kaasbjerg , K. S. Thygesen

For materials which are incorrectly predicted by density functional theory to be metallic, an iterative procedure must be adopted in order to perform GW calculations. In this paper we test two iterative schemes based on the quasi-particle…

Materials Science · Physics 2007-05-23 V. A. Popa , G. Brocks , P. J. Kelly

Within many-body perturbation theory, Hedin's formalism offers a systematic way to iteratively compute the self-energy $\Sigma$ of any interacting system, provided one can evaluate the interaction vertex $\Gamma$ exactly. This is however…

Chemical Physics · Physics 2022-11-04 Carlos Mejuto-Zaera , Vojtěch Vlček

The GW approximation in electronic structure theory has become a widespread tool for predicting electronic excitations in chemical compounds and materials. In the realm of theoretical spectroscopy, the GW method provides access to charged…

Materials Science · Physics 2019-12-11 Dorothea Golze , Marc Dvorak , Patrick Rinke

We study quasi-stationary states (QSS) resulting from violent relaxation in the one-dimensional self-gravitating "sheet model", revisiting in particular the question of the adequacy of the theory of Lynden-Bell (LB) to describe them. For…

Statistical Mechanics · Physics 2013-05-29 Michael Joyce , Tirawut Worrakitpoonpon

We present a new all-electron, augmented-wave implementation of the GW approximation using eigenfunctions generated by a recent variant of the full-potential LMTO method. The dynamically screened Coulomb interaction W is expanded in a mixed…

Materials Science · Physics 2009-11-07 Takao Kotani , Mark van Schilfgaarde

The quasiparticle electronic structure and optical excitation of anatase TiO$_2$ is determined within the framework of many-body perturbation theory (MBPT) by combining the $G_0W_0$ method and the Bethe-Salpeter Equation (BSE). A modified…

Materials Science · Physics 2021-12-07 Sruthil Lal S. B , D Murali , Matthias Posselt , Assa Aravindh Sasikala Devi , Alok Sharan

Accurate predictions of charge excitation energies of molecules in the disordered condensed phase are central to the chemical reactivity, stability, and optoelectronic properties of molecules and critically depend on the specific…

Chemical Physics · Physics 2021-08-25 Guorong Weng , Vojtech Vlcek

The Hubbard model on a semi-infinite three-dimensional lattice is considered to investigate electron-correlation effects at single-crystal surfaces. The standard second-order perturbation theory in the interaction U is used to calculate the…

Strongly Correlated Electrons · Physics 2009-10-30 M. Potthoff , W. Nolting

We present algorithmic and implementation details for the fully self-consistent finite-temperature $GW$ method in Gaussian Bloch orbitals for solids. Our implementation is based on the finite-temperature Green's function formalism in which…

Materials Science · Physics 2022-12-14 Chia-Nan Yeh , Sergei Iskakov , Dominika Zgid , Emanuel Gull

A stochastic cumulant GW method is presented, allowing us to map the evolution of photoemission spectra, quasiparticle energies, lifetimes and emergence of collective excitations from molecules to bulk-like systems with up to thousands of…

Mesoscale and Nanoscale Physics · Physics 2018-03-21 Vojtech Vlcek , Eran Rabani , Daniel Neuhauser