title: Toward Ab Initio Optical Spectroscopy of the Fenna-Matthews-Olson Complex.
abstract: We present progress toward a first-principles parametrization 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 interpigment 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.
authors: †TCM Group, Cavendish Laboratory, 19 JJ Thomson Ave, Cambridge CB3 0HE, United Kingdom.|‡Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States.
authors: Daniel J
authors: DJ
authors: Cole
authors: †TCM Group, Cavendish Laboratory, 19 JJ Thomson Ave, Cambridge CB3 0HE, United Kingdom.
authors: Alex W
authors: AW
authors: Chin
authors: †TCM Group, Cavendish Laboratory, 19 JJ Thomson Ave, Cambridge CB3 0HE, United Kingdom.|§Departments of Materials and Physics, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom.
authors: Nicholas D M
authors: ND
authors: Hine
authors: §Departments of Materials and Physics, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom.
authors: Peter D
authors: PD
authors: Haynes
authors: †TCM Group, Cavendish Laboratory, 19 JJ Thomson Ave, Cambridge CB3 0HE, United Kingdom.
authors: Mike C
authors: MC
authors: Payne
keywords: ab initio Hamiltonian; density functional theory; optical absorption spectrum; photosynthesis; pigment−protein complex