Molecular modeling of spectroscopy and quantum phenomena in light-harvesting complexes

• Applicant: Professor Dr. Ulrich Kleinekathöfer
• Subject Area: Theoretical Chemistry: Molecules, Materials, Surfaces ; Theoretical Chemistry: Electronic Structure, Dynamics, Simulation
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 226668712

In photosynthesis the energy of sunlight is captured by light-harvesting complexes and subsequently converted into chemical energy. Goal of the current project is to understand the subtle relationship between structure and function in light-harvesting complexes of photosynthetic systems. The system of interest is a light-harvesting complexes of marine cryptophytes, more specifically the water-soluble phycoerythrin 545. Molecular-level modeling shall allow to bridge the gap between the known crystal structures and the optical properties of the molecular aggregates. Starting from the crystal structure, molecular dynamics simulations are planned to obtain the thermal fluctuations of the nuclear positions as input for quantum chemical calculations. The results from the quantum chemical calculations are then used in quantum dynamical calculations of excitation dynamics and in the determination of optical properties such as the electronic two-dimensional correlation spectroscopy. During this computational project, several approximation shall be lifted which were employed in previous simulations of other light-harvesting systems. Furthermore, the study should yield a theoretical and atomistic picture of the reported long-lived quantum coherences at room temperature in the cryptophytes complexes.

• DFG Programme: Research Grants