Electronic excitation in molecular

Electronic excitations in molecular aggregates have received considerable attention from theoretists and experimentalists in recent years. Much of the work has focused on excitonic transport in molecular crystals (J.), in sub s t i t u 11 o na 11 y disordered mixed crystals (2.) and in amorphous structures (3.). Furthermore, excitation energy transfer (EET) has been studied in fluorescence concentration depolarization of donor molecules in solution (4.) as well as in excited-state energy transfer of donor -acceptor dyes in condensed phase systems (5.). 

Figure 4.1 Pictorial representation of the many-body [right] and singleparticle [left] representation of electronic excitations in molecular systems. The labels S and T denote singlet and triplet states, respectively.

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