Transient absorption spectra of excitation energy transfer in supramolecular complexes: A mixed quantum-classical description of pheophorbide-a systems

► MD simulations of a pheophorbide-a complex are carried out. ► Utilizing precalculated PESs the energy gap fluctuation is calculated. ► Schrödinger equation is solved including time dependent electromagnetic field. ► Transient absorbance and there from transient anisotropy are calculated. ► Timescale of excitation energy transfer is uncovered and matches previous results.