SITE INHOMOGENEITY AND EXCITON DELOCALIZATION IN THE PHOTOSYNTHETIC ANTENNA

The influence of energy disorder on exciton states of molecular aggreg ates (the dimer and the circular aggregate) was analyzed. The dipole s trength and inhomogeneous line shapes of exciton states were calculate d by means of numerical diagonalization of Hamiltonian with diagonal e nergy disorder without intersite correlation. The disorder degree corr esponding to destruction of coherent exciton states was estimated. The circular aggregates were treated as a model of light-harvesting anten na structures of photosynthetic bacteria. It was concluded that the si te inhomogeneity typical for LH1 and LH2 complexes of purple bacteria cannot significantly influence the exciton delocalization over the who le antenna.