CHARGE-TRANSFER STATES OF THE REACTION-CENTER

The energies of the low lying charge transfer states relevant for the photoinduced charge separation are analysed for Rps, viridis. The main prosthetic groups consisting of the special pair dimer P, the two adj acent monomers B-L, and B-M and the two pheophytines H-L and H-M are t reated together with the surrounding residues quantum mechanically wit hin a supermolecule approach on the basis of an INDO approximation. Hi gh order configuration interactions are incorporated to account for po larization effects and long range electrostatic effects of the protein are considered. The results are analyzed with regard to symmetry brea king effects between the L- and the M-branch. Internal reorganization effects within the dimer are also discussed. (C) 1998 Elsevier Science B.V. All rights reserved.