Berlin 2012 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 7: Poster: Biopolymers and Biomaterials (jointly with BP)

CPP 7.6: Poster

Montag, 26. März 2012, 17:30–19:30, Poster A

Excitation energy transfer dynamics in the light-harvesting complex LH2 determined by a mixed quantum-classical approach — •Jörg Liebers¹, Carsten Olbrich^1,2, Mortaza Aghtar¹, Michael Schreiber², and Ulrich Kleinekathöfer¹ — ¹Jacobs University Bremen, Germany — ²Chemnitz University of Technology, Germany

In photosynthesis the harvesting of sun light is done by light-harvesting antenna complexes containing chlorophyll and carotenoid molecules. Starting from the available crystal structure of the light-harvesting systems 2 (LH2) of a purple bacterium all-atom classical molecular-dynamics (MD) simulations were applied to obtain the motion of the nuclei due to thermal fluctuations [1]. These fluctuations provide the input for quantum chemical calculations to calculate the excitation energies of the Q_y states of the single bacteriochlorophyll (BChl) molecules and also the Coulomb couplings between them. Using these time series of excitation energies and couplings, the spectral density and time-dependent Hamiltonians for this system were constructed which allows for a quantum dynamical investigation of the excitation energy transfer processes in the LH2 complex [2]. Here we use ensemble averaged wave packet dynamics with a quantum correction for temperature effects to calculate excitation dynamics and optical properties.

[1] C. Olbrich, U. Kleinekathöfer, J. Phys. Chem. B 114, 12427 (2010).

[2] C. Olbrich, J. Liebers, U. Kleinekathöfer, phys. stat. sol. (b) 248, 393 (2011).