2014/11/12 by David M. Wilkins, Wilkins, David M., Nikesh S. Dattani +1 · 3 citations
Biochemistry, Genetics and Molecular Biology · Chemistry · Physics and Astronomy · #81-08 #81V55 #Biological Physics (physics.bio-ph) #Chemical Physics (physics.chem-ph) #FOS: Biological sciences #FOS: Physical sciences #J.2 #Photochemistry and Electron Transfer Studies #Photosynthetic Processes and Mechanisms #Quantitative Methods (q-bio.QM) #Quantum Physics (quant-ph) #Spectroscopy and Quantum Chemical Studies
paper · pdf · doi:10.48550/arxiv.1411.3654
openalex publication_date 2014/11/12 · openalex created_date 2022/10/02 · openalex updated_date 2026/07/28
We develop and present an improvement to the conventional technique for\nsolving the Hierarchical Equations of Motion which reduces the memory cost by\nmore than 75% while retaining the same convergence rate and accuracy. This\nallows for a full calculation of the population dynamics of the 24-site FMO\ntrimer for long timescales with very little effort, and we present the first\nfully converged, exact results for the 7-site subsystem of the monomer, and for\nthe full 24-site trimer. Owing to this new approach, our numerically exact\n24-site, 2-exponential results are the most demanding HEOM calculations\nperformed to date, surpassing the 50-site, 1-exponential results of Strumpfer\nand Schulten [2012, J. Chem. Thy. & Comp., 8, 2808]. We then show where our\nexact 7-site results deviate from the approximation of Ishizaki and Fleming\n[2009, Proc. Natl. Acad. Sci. USA, 106, 17255]. Our exact results are then\ncompared to calculations using the incoherent Forster theory, and it is found\nthat the energy transfer from the antenna to the reaction center occurs more\nthan 50 times faster than the fluorescence lifetime of the excitation, whether\nor not coherence is considered. This means that coherence is not likely to\nimprove the efficiency of the photosynthesis. In fact, the incoherent theory\noften tends to over-predict the rates of energy transfer, suggesting that in\nsome cases electronic coherence may actually slow down the photosynthetic\nprocess.\n