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VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20261008T011039Z
UID:https://www.mpsd.mpg.de/events/11596/17181
DTSTART:20171130T130000Z
DTEND:20171130T150000Z
CLASS:PUBLIC
CREATED:20171115T122722Z
DESCRIPTION:Two challenges in the simulation of excitation energy transfer 
 and optical spectra of pigment-protein complexes are the equal magnitude o
 f the excitonic and the exciton-vibrational coupling and the structure-bas
 ed parametrization of the Hamiltonian (for review see ref. 1). We have dev
 eloped quantum chemical/electrostatics/normal mode analysis (NMA) schemes 
 to calculate optical transition energies of pigments in their binding site
  in the protein (site energies)\, interpigment excitonic couplings and the
  spectral density of the pigment-protein coupling. Our NMA of the spectral
  density shows that the modulation of site energies is an order of magnitu
 de stronger than that of the excitonic couplings and that also in the basi
 s of delocalized exciton states the diagonal exciton-vibrational coupling 
 dominates [2]. This result explains the good performance of our earlier ti
 me-local lineshape theory [3]\, in which the diagonal elements are treated
  exactly and the off-diagonal elements in Markov and secular approximation
 s\, and triggered a new development that takes into account the finite rel
 axation time of nuclei during exciton relaxation [4]. I will give a summar
 y of our theory development and present applications on a small model syst
 em (water soluble chlorophyll binding protein -WSCP) and large photosystem
  II core particles. In the case of WSCP we have developed and applied a th
 eory of holeburning spectroscopy [5] that goes beyond the standard two-lev
 el system approach and allows for a quantitative description of experiment
 al data\, revealing the lifetime of the upper exciton state\, in excellent
  agreement with results from 2D electronic spectroscopy and our earlier pr
 ediction [6]. In the case of photosystem II I will present results of the 
 parametrization of the exciton Hamiltonian of its subunits [7-9]. These pa
 rameters were used to describe VIS/IR pump-probe data on single crystals o
 f PSII core particles [10] that allowed for a verification of our earlier 
 prediction [11] on the relative timescale of excitation energy and charge 
 transfer in this system. The results are discussed in terms of photoprotec
 tion scenarios that allow photosystem II to switch between a light harvest
 ing and an excitation energy quenching mode protecting the reaction center
 .\nSpeaker: Thomas Renger
LAST-MODIFIED:20171116T122801Z
LOCATION:CFEL (Bldg. 99)\, Room: Seminar Room IV\, O1.111
ORGANIZER;CN=R. J. Dwayne Miller:mailto:
SUMMARY:MPSD ARD Seminar: Thomas Renger - Structure-based theory of light-h
 arvesting in photosynthesis
URL;VALUE=URI:https://www.mpsd.mpg.de/events/11596/17181
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