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Interaction of Dark Excited States: Comparison of Computational Approaches

A systematic theoretical study of the electronic interaction of dark excited states in a model system, formaldehyde dimer is reported. Using the fragment transition density scheme, we estimate the excitonic interaction in different configurations of the dimer. The excited state properties of the system are computed with several quantum mechanical methods. We show that the orbital interaction of the monomers rather than Coulomb interaction of their transition quadrupoles gives the major contribution to the coupling at intermolecular distances shorter than 5 Å. It is found that the exitonic interaction alters drastically by conformational changes. Benchmark couplings computed with EOM CCSD, MS-CASPT2, CASSCF, TD DFT, CIS, and INDO/S and different basis sets are provided. The evaluation of the calculations shows that the TD cam-B3LYP scheme performs best, giving good estimates for all considered structures. In contrast, the TD B3LYP scheme leads to drastically overestimated values. The data obtained using the Tamm-Dancoff approximation are similar to the TD DFT results. CASSCF and CIS calculations underestimate the coupling, indicating that dynamic electron correlation may have a large effect on the short-range coupling. The INDO/S method fails to describe the excited state interaction both at short and long distances

It was a great pleasure to work with Marshall during his long-term visit to Technical University of Munich. I am very grateful for his inspiring and helpful insights into the theoretical and computational modeling of electron transfer. Financial support from MICINN (Ministry of Science and Innovation, Spain) was provided by Grant CTQ2011-26573

© Journal of Physical Chemistry B, 2015, vol. 119, núm. 24p. 7417-7421

American Chemical Society (ACS)

Author: Voityuk, Alexander A.
Date: 2015
Abstract: A systematic theoretical study of the electronic interaction of dark excited states in a model system, formaldehyde dimer is reported. Using the fragment transition density scheme, we estimate the excitonic interaction in different configurations of the dimer. The excited state properties of the system are computed with several quantum mechanical methods. We show that the orbital interaction of the monomers rather than Coulomb interaction of their transition quadrupoles gives the major contribution to the coupling at intermolecular distances shorter than 5 Å. It is found that the exitonic interaction alters drastically by conformational changes. Benchmark couplings computed with EOM CCSD, MS-CASPT2, CASSCF, TD DFT, CIS, and INDO/S and different basis sets are provided. The evaluation of the calculations shows that the TD cam-B3LYP scheme performs best, giving good estimates for all considered structures. In contrast, the TD B3LYP scheme leads to drastically overestimated values. The data obtained using the Tamm-Dancoff approximation are similar to the TD DFT results. CASSCF and CIS calculations underestimate the coupling, indicating that dynamic electron correlation may have a large effect on the short-range coupling. The INDO/S method fails to describe the excited state interaction both at short and long distances
It was a great pleasure to work with Marshall during his long-term visit to Technical University of Munich. I am very grateful for his inspiring and helpful insights into the theoretical and computational modeling of electron transfer. Financial support from MICINN (Ministry of Science and Innovation, Spain) was provided by Grant CTQ2011-26573
Format: application/pdf
ISSN: 1520-6106 (versió paper)
1520-5207 (versió electrònica)
Document access: http://hdl.handle.net/10256/11462
Language: eng
Publisher: American Chemical Society (ACS)
Collection: MICINN/PN 2012-2014/CTQ2011-26573
Reproducció digital del document publicat a: http://dx.doi.org/10.1021/jp511035p
Articles publicats (D-Q)
Is part of: © Journal of Physical Chemistry B, 2015, vol. 119, núm. 24p. 7417-7421
Rights: Tots els drets reservats
Subject: Química de l’estat excitat
Excited state chemistry
Química quàntica
Quantum chemistry
Transferència de càrrega
Charge transfer
Title: Interaction of Dark Excited States: Comparison of Computational Approaches
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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