Download presentation
Presentation is loading. Please wait.
Published bySherilyn Rice Modified over 9 years ago
1
Semiclassical approach for all-atom nonadiabatic simulations of excitation energy transfer processes in photosynthetic complexes Young Min Rhee Department of Chemistry POSTECH (Pohang University of Science and Technology)
2
Young Min Rhee, 2013 http://singlet.postech.ac.kr Quantum coherence in photosynthesis Debates, debates, debates, …
3
Young Min Rhee, 2013 Detailed look? http://singlet.postech.ac.kr Theoretical approaches!
4
Young Min Rhee, 2013 http://singlet.postech.ac.kr Quantum coherence vs hopping Classical hopping
5
Young Min Rhee, 2013 http://singlet.postech.ac.kr Quantum coherence vs hopping Classical hopping
6
Young Min Rhee, 2013 http://singlet.postech.ac.kr Quantum coherence vs hopping Coherent transfer Can be faster!
7
Young Min Rhee, 2013 http://singlet.postech.ac.kr Classroom chaos…
8
Young Min Rhee, 2013 http://singlet.postech.ac.kr Class I constant H + abstract model bath Class II more realistic H, but ground state-like bath Class III bath relaxation upon electronic changes Classes of theoretical approaches H.W. Kim; A. Kelly; J.W. Park; YMR, JACS 134, 11640 (2012)
9
Young Min Rhee, 2013 Importance of the model consistency What if the potential is switched for better accuracy? Potential exaggeration in One potential model should be adopted all the time http://singlet.postech.ac.kr
10
Young Min Rhee, 2013 http://singlet.postech.ac.kr Class I constant H + abstract model bath Class II more realistic H but ground state-like bath Class III bath relaxation upon electronic changes Classes of theoretical approaches
11
Young Min Rhee, 2013 http://singlet.postech.ac.kr Class I constant H + abstract model bath Class II more realistic H but ground state-like bath Class III bath relaxation upon electronic changes Classes of theoretical approaches
12
Young Min Rhee, 2013 http://singlet.postech.ac.kr Modeling for the chromophore complex Diagonals: force-field approach Off-diagonals: transition charge electrostatic potential (TrESP) [Madjet et al. JPCB 110, 17268 (2006)] Fluctuations with all-atom interaction
13
Young Min Rhee, 2013 http://singlet.postech.ac.kr Electronic structure theory Direct passage toward studying dynamics Modeling for the chromophore complex
14
Young Min Rhee, 2013 Can this be reliable? http://singlet.postech.ac.kr Decent to good agreement!
15
Young Min Rhee, 2013 http://singlet.postech.ac.kr mapping formalism All atom Semiclassical approach H. Kim; A. Nassimi; R. Kapral, JCP 129, 084102 (2008) A. Kelly; YMR, JPCL 2, 808 (2011) Partial Wigner transform
16
Young Min Rhee, 2013 http://singlet.postech.ac.kr Semiclassical approach: PBME Mapping approach: N quantum states N fictitious harmonic oscillator Dynamics of electronic states : Dynamics of (r, p) with Hamiltonian (Classical-looking) Newton-like mechanics toward multiple surface dynamics! Modeling efforts
17
Young Min Rhee, 2013 http://singlet.postech.ac.kr Confinement versus electrostatics Mutation study Confinement dominates over electrostatics for FMO Wild type ALA-mutant Electrostatic mutant H.W. Kim; A. Kelly; J.W. Park; YMR, JACS 134, 11640 (2012)
18
Young Min Rhee, 2013 http://singlet.postech.ac.kr Nature of initial state When started from non-oscillatory initial state Fluctuation “kicks” stationary into oscillatory Still becomes oscillatory after ~20 fs
19
Young Min Rhee, 2013 http://singlet.postech.ac.kr Vibrational effects? With active chromophore vibration With silenced chromophore vibration No coherence??? Classical nature: exaggeration of vibrational effect (faster decoherence) H.W. Kim; A. Kelly; J.W. Park; YMR, JACS 134, 11640 (2012)
20
Young Min Rhee, 2013 http://singlet.postech.ac.kr Ensemble versus single molecules Each is coherent in its own manner “Rigid” protein keeps coherence Coherent even with classical vibrations
21
Young Min Rhee, 2013 http://singlet.postech.ac.kr Future prospects Better QCLE than PBME? Semi-classical but yet classical Zero-point energy leaking Currently, horrible when states are largely separated Better potential for more reliable modeling? Different systems with QM effects?
22
Young Min Rhee, 2013 http://singlet.postech.ac.kr Conclusions All-atom level insight: POSSIBLE!!! Rigid nature of protein Chromophore alignment maintenance Coherent coupling Fidelity in photosynthesis? Flexible nature of protein Coupling fluctuation Diversity? H.W. Kim; A. Kelly; J.W. Park; YMR, JACS 134, 11640 (2012)
23
Young Min Rhee, 2013 http://singlet.postech.ac.kr Acknowledgements Aaron Kelly: PBME Hyun Woo Kim: MD interface Jae Woo Park: IM/MM Sun Mi Choi Weon-Gyu Lee Chang Woo Kim Postech (equipment) KOSEF / KRF / IBS ( \$ ) KISTI (CPU time) Q-Chem And YOU!!!
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.