Daniel Cole

Toward ab initio Optical Spectroscopy of the Fenna-Matthews-Olson Complex

Daniel J. Cole,1,2 Alex W. Chin,1 Nicholas D. M. Hine,1 Peter D. Haynes,3 Mike C. Payne1
1Theory of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK
2Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
3Departments of Materials and Physics, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom

We present progress toward a first principles parameterization of the Hamiltonian of the Fenna-Matthews-Olson pigment-protein complex - a molecule that has become key to understanding the role of quantum dynamics in photosynthetic exciton energy transfer. To this end, we have performed fully quantum mechanical calculations on each of the seven bacteriochlorophyll pigments that make up the complex, including a significant proportion of their protein environment (more than 2000 atoms), using linear-scaling density functional theory exploiting a recent development for the computation of excited states. Local pigment transition energies and inter-pigment coupling between optical transitions have been calculated and are in good agreement with the literature consensus. Comparisons between simulated and experimental optical spectra point toward future work that may help to elucidate important design principles in these nanoscale devices.

Journal of Physical Chemistry Letters 4, 4206 (2013)