Dynamical simulation of the optical response of photosynthetic pygments

MA. BELÉN OVIEDO; CHRISTIAN F. A. NEGRE; CRISTIÁN G. SÁNCHEZ

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Lugar: Londres; Año: 2009

1463-9076

From time integration of the electron dynamics under a density functional tight binding Hamiltonian in the presence of external time varying electric fields, we obtain the absorption spectra of a series of chlorophylls and bacteriochlorophylls. We obtain good agreement with the observed experimental energies as well as with fully ab initio results in the literature for the main absorption bands. As a first step towards an atomistic description of energy transfer between chromophores in photosynthetic antenna systems we calculate the coupling energy between the excitations of two chlorophyll a molecules as a function of distance as well as the transfer of energy between these when one of them is subjected to laser illumination.