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

Result code in 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>

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10300 - Physical sciences

Project

<a href="/en/project/GA22-22419S" target="_blank" >GA22-22419S: Molecular spintronics: control of spin-orbit fields</a><br>

Continuities

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

Publication year

2024

Confidentiality

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

Name of the periodical

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

1463-9084

Volume of the periodical

26

Issue of the periodical within the volume

3

Country of publishing house

GB - UNITED KINGDOM

Number of pages

7

Pages from-to

2127-2133

UT code for WoS article

001128875600001

EID of the result in the Scopus database

2-s2.0-85180579096