TY - GEN A1 - Megow, Jörg A1 - Röhr, Merle I. S. A1 - Schmidt am Busch, Marcel A1 - Renger, Thomas A1 - Mitrić, Roland A1 - Kirstein, Stefan A1 - Rabe, Jürgen P. A1 - May, Volkhard T1 - Site-dependence of van der Waals interaction explains exciton spectra of double-walled tubular J-aggregates N2 - The simulation of the optical properties of supramolecular aggregates requires the development of methods, which are able to treat a large number of coupled chromophores interacting with the environment. Since it is currently not possible to treat large systems by quantum chemistry, the Frenkel exciton model is a valuable alternative. In this work we show how the Frenkel exciton model can be extended in order to explain the excitonic spectra of a specific double-walled tubular dye aggregate explicitly taking into account dispersive energy shifts of ground and excited states due to van der Waals interaction with all surrounding molecules. The experimentally observed splitting is well explained by the site-dependent energy shift of molecules placed at the inner or outer side of the double-walled tube, respectively. Therefore we can conclude that inclusion of the site-dependent dispersive effect in the theoretical description of optical properties of nanoscaled dye aggregates is mandatory. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 191 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-79978 SP - 6741 EP - 6747 ER - TY - JOUR A1 - Megow, Jörg A1 - Röhr, Merle I. S. A1 - Schmidt am Busch, Marcel A1 - Renger, Thomas A1 - Mitrić, Roland A1 - Kirstein, Stefan A1 - Rabe, Jürgen P. A1 - May, Volkhard T1 - Site-dependence of van der Waals interaction explains exciton spectra of double-walled tubular J-aggregates JF - Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies N2 - The simulation of the optical properties of supramolecular aggregates requires the development of methods, which are able to treat a large number of coupled chromophores interacting with the environment. Since it is currently not possible to treat large systems by quantum chemistry, the Frenkel exciton model is a valuable alternative. In this work we show how the Frenkel exciton model can be extended in order to explain the excitonic spectra of a specific double-walled tubular dye aggregate explicitly taking into account dispersive energy shifts of ground and excited states due to van der Waals interaction with all surrounding molecules. The experimentally observed splitting is well explained by the site-dependent energy shift of molecules placed at the inner or outer side of the double-walled tube, respectively. Therefore we can conclude that inclusion of the site-dependent dispersive effect in the theoretical description of optical properties of nanoscaled dye aggregates is mandatory. Y1 - 2015 U6 - https://doi.org/10.1039/c4cp05945j SN - 1463-9084 SN - 1463-9076 VL - 17 IS - 10 SP - 6741 EP - 6747 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Megow, Jörg A1 - Röhr, Merle I. S. A1 - Busch, Marcel A1 - Renger, Thomas A1 - Mitric, Roland A1 - Kirstein, Stefan A1 - Rabe, Jürgen P. A1 - May, Volkhard T1 - Site-dependence of van der Waals interaction explains exciton spectra of double-walled tubular J-aggregates JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - The simulation of the optical properties of supramolecular aggregates requires the development of methods, which are able to treat a large number of coupled chromophores interacting with the environment. Since it is currently not possible to treat large systems by quantum chemistry, the Frenkel exciton model is a valuable alternative. In this work we show how the Frenkel exciton model can be extended in order to explain the excitonic spectra of a specific double-walled tubular dye aggregate explicitly taking into account dispersive energy shifts of ground and excited states due to van der Waals interaction with all surrounding molecules. The experimentally observed splitting is well explained by the site-dependent energy shift of molecules placed at the inner or outer side of the double-walled tube, respectively. Therefore we can conclude that inclusion of the site-dependent dispersive effect in the theoretical description of optical properties of nanoscaled dye aggregates is mandatory. Y1 - 2015 U6 - https://doi.org/10.1039/c4cp05945j SN - 1463-9076 SN - 1463-9084 VL - 17 IS - 10 SP - 6741 EP - 6747 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Titov, Evgenii A1 - Kopp, Tristan A1 - Hoche, Joscha A1 - Humeniuk, Alexander A1 - Mitrić, Roland T1 - (De)localization dynamics of molecular excitons BT - comparison of mixed quantum-classical and fully quantum treatments JF - Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies N2 - Molecular excitons play a central role in processes of solar energy conversion, both natural and artificial. It is therefore no wonder that numerous experimental and theoretical investigations in the last decade, employing state-of-the-art spectroscopic techniques and computational methods, have been driven by the common aim to unravel exciton dynamics in multichromophoric systems. Theoretically, exciton (de)localization and transfer dynamics are most often modelled using either mixed quantum-classical approaches (e.g., trajectory surface hopping) or fully quantum mechanical treatments (either using model diabatic Hamiltonians or direct dynamics). Yet, the terms such as "exciton localization" or "exciton transfer" may bear different meanings in different works depending on the method in use (quantum-classical vs. fully quantum). Here, we relate different views on exciton (de)localization. For this purpose, we perform molecular surface hopping simulations on several tetracene dimers differing by a magnitude of exciton coupling and carry out quantum dynamical as well as surface hopping calculations on a relevant model system. The molecular surface hopping simulations are done using efficient long-range corrected time-dependent density functional tight binding electronic structure method, allowing us to gain insight into different regimes of exciton dynamics in the studied systems. Y1 - 2022 U6 - https://doi.org/10.1039/d2cp00586g SN - 1463-9076 SN - 1463-9084 VL - 24 IS - 20 SP - 12136 EP - 12148 PB - Royal Society of Chemistry CY - Cambridge ER -