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Simulation of Excitation by Sunlight in Mixed Quantum-Classical Dynamics

revised on 14.05.2020 and posted on 15.05.2020 by Mario Barbatti
This paper proposes a method to simulate nonadiabatic dynamics initiated by thermal light, including solar radiation, in the frame of mixed quantum-classical (MQC) methods, like surface hopping. The method is based on the Chenu-Brumer approach, which treats the thermal radiation as an ensemble of coherent pulses. It is composed of three steps, 1) sampling initial conditions from a broad blackbody spectrum, 2) dynamics propagation using conventional methods, and 3) ensemble averaging considering the field and realization time of the pulses. The application of MQC dynamics with pulse ensemble (MQC-PE) to a model system of nucleic acid photophysics showed the emergence of a steady excited-state population. In another test case, modeling retinal photophysics, MQC-PE predicted that although the photoisomerization occurs within 200 fs, it may take tens of microseconds of continuous solar irradiation to photoactivate a single retinal. Such emergent long timescales may impact our understanding of biological and technological phenomena occurring under solar radiation.


European Research Council (ERC) Advanced grant SubNano (Grant agreement 832237)

FetOpen grant BoostCrop (Grant agreement 828753)


Email Address of Submitting Author


Aix Marseille Univ, CNRS, ICR



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest.

Version Notes

Version 5: Fix typos and minor changes in style and orthography. Version 4: Fix typos and minor changes in style and orthography. New funding source added. Version 3: Table 1 added. Version 2: New notes added to SI.