Work

Theory and Simulation of the Environmental Effects on FMO Electronic Transitions

Year: 2011

Type: article

Abstract: Long-lived quantum coherence has been experimentally observed in the Fenna-Matthews-Olson (FMO) light-harvesting complex. It is much debated which role thermal effects play and if the observed low-temperature behavior arises also at physiological temperature. To contribute to this debate we use molecular dynamics simulations to study the coupling between the protein environment and the vertical excitation energies of individual bacteriochlorophyll molecules in the FMO complex of the green sulphur bacterium Chlorobaculum tepidum. The so-called spectral densities, which account for the environmental influence on the excited state dynamics, are determined from temporal autocorrelation functions of the energy gaps between ground and first excited states of the individual pigments. Although the overall shape of the spectral density is found to be rather similar for all pigments, variations in their magnitude can be seen. Differences between the spectral densities for the pigments of the FMO monomer and FMO trimer are also presented.

Source: The Journal of Physical Chemistry Letters

DOI: 10.1021/jz2007676

Authors: Carsten Olbrich, Johan Strümpfer, Klaus Schulten, Ulrich Kleinekathöfer

Institutions: Constructor University, University of Illinois Urbana-Champaign

Language: English

Topic: Spectroscopy and Quantum Chemical Studies

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, National Center for Research Resources

Award: RESOURCE FOR MACROMOLECULAR MODELING AND BIOINFORMATICS