Vertical ionization potential benchmark for unitary coupled-cluster and algebraic-diagrammatic construction methods

• Verfasst von: Dempwolff, Adrian [VerfasserIn]
• Verfasst von: Hodecker, Manuel [VerfasserIn]
• Verfasst von: Dreuw, Andreas [VerfasserIn]
• Titel: Vertical ionization potential benchmark for unitary coupled-cluster and algebraic-diagrammatic construction methods
• Verf.angabe: Adrian L. Dempwolff, Manuel Hodecker, and Andreas Dreuw
• E-Jahr: 2022
• Jahr: 4 February 2022
• Umfang: 8 S.
• Fussnoten: Gesehen am 17.03.2022
• Titel Quelle: Enthalten in: The journal of chemical physics
• Ort Quelle: Melville, NY : American Institute of Physics, 1933
• Jahr Quelle: 2022
• Band/Heft Quelle: 156(2022), 5, Artikel-ID 054114, Seite 1-8
• ISSN Quelle: 1089-7690
• DOI: doi:10.1063/5.0079047
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1795750847

Abstract

The performance of several methods for the calculation of vertical ionization potentials (IPs) or, more generally, electron-detachment energies based on unitary coupled-cluster (UCC) theory and the algebraic-diagrammatic construction (ADC) scheme is evaluated with respect to benchmark data computed at the level of equation-of-motion coupled-cluster theory, including single, double, and triple excitations (IP-EOM-CCSDT). Based on a statistical evaluation of about 200 electron-detached states of 41 molecules, the second-order methods IP-ADC(2) and IP-UCC2 show modest accuracies with IP-EOM-CCSDT as reference, exposing a mean signed error and a standard deviation of the error of −0.54 ± 0.50 and −0.49 ± 0.54 eV, respectively, accompanied by a mean absolute error (MAE) of 0.61 and 0.58 eV, respectively. The strict third-order IP-ADC method demonstrates an accuracy of 0.26 ± 0.35 eV (MAE = 0.35 eV), while the IP-UCC3 method is slightly more accurate with 0.24 ± 0.26 eV (MAE = 0.29 eV). Employing the static self-energy computed using the Dyson expansion method (DEM) improves the IP-ADC(3) performance to 0.27 ± 0.28 eV, with the mean absolute error of this method being 0.32 eV. However, employing the simpler improved fourth-order scheme Σ(4+) for the static self-energy provides almost identical results as the DEM. Based on the quality of the present benchmark results, it therefore appears not necessary to use the computationally more demanding DEM.