title: Getting excited: challenges in quantum-classical studies of excitons in polymeric systems.
abstract: A combination of classical molecular dynamics (MM/MD) and quantum chemical calculations based on the density functional theory (DFT) was performed to describe the conformational properties of diphenylethyne (DPE), methylated-DPE and poly para phenylene ethynylene (PPE). DFT calculations were employed to improve and develop force field parameters for MM/MD simulations. Many-body Green's function theory within the GW approximation and the Bethe-Salpeter (GW-BSE) equation were utilized to describe the excited states of the systems. The reliability of the excitation energies based on the MM/MD conformations was examined and compared to the excitation energies from DFT conformations. The results show an overall agreement between the optical excitations based on MM/MD conformations and DFT conformations. This allows for the calculation of excitation energies based on MM/MD conformations.
authors.affiliation: Department of Mathematics and Computer Science & Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands. b.baumeier@tue.nl m.e.j.karttunen@tue.nl.
authors.forename: Behnaz
authors.initials: B
authors.lastname: Bagheri
authors.affiliation: Department of Mathematics and Computer Science & Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands. b.baumeier@tue.nl m.e.j.karttunen@tue.nl.
authors.forename: Björn
authors.identifier: http://orcid.org/0000-0002-6077-0467
authors.initials: B
authors.lastname: Baumeier
authors.affiliation: Department of Mathematics and Computer Science & Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands. b.baumeier@tue.nl m.e.j.karttunen@tue.nl.
authors.forename: Mikko
authors.initials: M
authors.lastname: Karttunen