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Large‐Scale Quantum Many‐Body Perturbation on Spin and Charge Separation in the Excited States of the Synthesized Donor–Acceptor Hybrid PBI–Macrocycle Complex
Author(s) -
Ziaei Vafa,
Bredow Thomas
Publication year - 2017
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201601244
Subject(s) - excited state , hybrid functional , density functional theory , ab initio , singlet state , excitation , perturbation theory (quantum mechanics) , ab initio quantum chemistry methods , acceptor , chemistry , quantum , molecular physics , atomic physics , chemical physics , physics , computational chemistry , quantum mechanics , molecule
The reliable calculation of the excited states of charge‐transfer (CT) compounds poses a major challenge to the ab initio community because the frequently employed method, time‐dependent density functional theory (TD‐DFT), massively relies on the underlying density functional, resulting in heavily Hartree–Fock (HF) exchange‐dependent excited‐state energies. By applying the highly sophisticated many‐body perturbation approach, we address the encountered unreliabilities and inconsistencies of not optimally tuned (standard) TD‐DFT regarding photo‐excited CT phenomena, and present results concerning accurate vertical transition energies and the correct energetic ordering of the CT and the first visible singlet state of a recently synthesized thermodynamically stable large hybrid perylene bisimide–macrocycle complex. This is a large‐scale application of the quantum many‐body perturbation approach to a chemically relevant CT system, demonstrating the system‐size independence of the quality of the many‐body‐based excitation energies. Furthermore, an optimal tuning of the ωB97X hybrid functional can well reproduce the many‐body results, making TD‐DFT a suitable choice but at the expense of introducing a range‐separation parameter, which needs to be optimally tuned.