Widening of the fundamental gap in cluster GW for metal-molecular interfaces

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F24%3A10473904" target="_blank" >RIV/00216208:11320/24:10473904 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=QX13~nGoRu" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=QX13~nGoRu</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d3cp04082h" target="_blank" >10.1039/d3cp04082h</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Widening of the fundamental gap in cluster GW for metal-molecular interfaces

Popis výsledku v původním jazyce

The GW approximation is very promising for an accurate first-principles description of charged excitations in single-molecule-metal interfaces. In the cluster approach for electronic transport across molecules, the infinite metal (with an adsorbed molecule) is replaced by a finite cluster whose volume should be incrementally increased to test the approach to the thermodynamic limit. Here we show that in GW, the approach to the thermodynamic limit will be much slower than in Kohn-Sham density-functional theory (DFT) because of the Coulomb interaction. To demonstrate this statement, we investigate spectral gaps in an ensemble of disordered sodium clusters in Kohn-Sham DFT, quasiparticle eigenvalue-self-consistent GW and Hartree-Fock. The fundamental gaps (i.e. difference between the lowest unoccupied and highest occupied level) in GW scale as N-1/3 on average, where N is the number of atoms. We demonstrate that this slow decrease artificially depletes the density of states at the Fermi level when the cluster is used to simulate a semi-infinite electrode. Therefore, the GW method cannot be taken as an out-of-the-box improvement of the DFT in cluster geometries, unless careful convergence checks are performed. While GW approximation is a promising improvement to the density functional theory electronic structure calculations, in context of cluster transport calculations, care has to be taken to ensure convergence of the electrode gap with cluster volume.

Název v anglickém jazyce

Widening of the fundamental gap in cluster GW for metal-molecular interfaces

Popis výsledku anglicky

The GW approximation is very promising for an accurate first-principles description of charged excitations in single-molecule-metal interfaces. In the cluster approach for electronic transport across molecules, the infinite metal (with an adsorbed molecule) is replaced by a finite cluster whose volume should be incrementally increased to test the approach to the thermodynamic limit. Here we show that in GW, the approach to the thermodynamic limit will be much slower than in Kohn-Sham density-functional theory (DFT) because of the Coulomb interaction. To demonstrate this statement, we investigate spectral gaps in an ensemble of disordered sodium clusters in Kohn-Sham DFT, quasiparticle eigenvalue-self-consistent GW and Hartree-Fock. The fundamental gaps (i.e. difference between the lowest unoccupied and highest occupied level) in GW scale as N-1/3 on average, where N is the number of atoms. We demonstrate that this slow decrease artificially depletes the density of states at the Fermi level when the cluster is used to simulate a semi-infinite electrode. Therefore, the GW method cannot be taken as an out-of-the-box improvement of the DFT in cluster geometries, unless careful convergence checks are performed. While GW approximation is a promising improvement to the density functional theory electronic structure calculations, in context of cluster transport calculations, care has to be taken to ensure convergence of the electrode gap with cluster volume.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10300 - Physical sciences

Projekt

<a href="/cs/project/GA22-22419S" target="_blank" >GA22-22419S: Molekulární spintronika: řízení spin-orbitálních polí</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

1463-9084

Svazek periodika

26

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

7

Strana od-do

2127-2133

Kód UT WoS článku

001128875600001

EID výsledku v databázi Scopus

2-s2.0-85180579096