Adapting algebraic diagrammatic construction schemes for the polarization propagator to problems with multi-reference electronic ground states exploiting the spin-flip ansatz

• Verfasst von: Lefrancois, Daniel [VerfasserIn]
• Verfasst von: Wormit, Michael [VerfasserIn]
• Verfasst von: Dreuw, Andreas [VerfasserIn]
• Titel: Adapting algebraic diagrammatic construction schemes for the polarization propagator to problems with multi-reference electronic ground states exploiting the spin-flip ansatz
• Verf.angabe: Daniel Lefrancois, Michael Wormit, and Andreas Dreuw
• E-Jahr: 2015
• Jahr: 28 September 2015
• Umfang: 10 S.
• Fussnoten: Gesehen am 11.12.2017
• Titel Quelle: Enthalten in: The journal of chemical physics
• Ort Quelle: Melville, NY : American Institute of Physics, 1933
• Jahr Quelle: 2015
• Band/Heft Quelle: 143(2015,12) Artikelnummer 124107, 10 Seiten
• ISSN Quelle: 1089-7690
• DOI: doi:10.1063/1.4931653
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1566235049

Abstract

For the investigation of molecular systems with electronic ground states exhibiting multi-reference character, a spin-flip (SF) version of the algebraic diagrammatic construction (ADC) scheme for the polarization propagator up to third order perturbation theory (SF-ADC(3)) is derived via the intermediate state representation and implemented into our existing ADC computer program adcman. The accuracy of these new SF-ADC(n) approaches is tested on typical situations, in which the ground state acquires multi-reference character, like bond breaking of H2 and HF, the torsional motion of ethylene, and the excited states of rectangular and square-planar cyclobutadiene. Overall, the results of SF-ADC(n) reveal an accurate description of these systems in comparison with standard multi-reference methods. Thus, the spin-flip versions of ADC are easy-to-use methods for the calculation of “few-reference” systems, which possess a stable single-reference triplet ground state.