  A remarkable amount of theoretical research has been carried out to elucidate
the physical origins of the recently observed long-lived quantum coherence in
the electronic energy transfer process in biological photosynthetic systems.
Although successful in many respects, several widely used descriptions only
include an effective treatment of the protein-chromophore interactions. In this
work, by combining an all-atom molecular dynamics simulation, time-dependent
density functional theory, and open quantum system approaches, we successfully
simulate the dynamics of the electronic energy transfer of the
Fenna-Matthews-Olson pigment-protein complex. The resulting characteristic
beating of populations and quantum coherences is in good agreement with the
experimental results and the hierarchy equation of motion approach. The
experimental absorption, linear and circular dichroism spectra and dephasing
rates are recovered at two different temperatures. In addition, we provide an
extension of our method to include zero-point fluctuations of the vibrational
environment. This work thus presents one of the first steps to explain the role
of excitonic quantum coherence in photosynthetic light-harvesting complexes
based on their atomistic and molecular description.
