INTERPLAY OF EXCITON OR ELECTRON-TRANSFER AND RELAXATION .2. TOKUYAMA-MORI APPROACH

Tokuyama-Mori theory together with canonical transformation but with q uantities of interest remaining untransformed is applied to the excito n- or electron-phonon system with site-diagonal linear coupling and fu ll exciton or electron density matrix; finite concentrations of the ca rriers are admitted. The result is applied to a particle on a symmetri c dimer. In contrast to recent calculations showing that time-convolut ion (Mori or generalized master equation) second-order (in coupling to phonons) approaches fail in providing genuine relaxation, independent (up to the initial time interval) of the degree of initial polaron fo rmation, the Tokuyama-Mori theory is illustrated to be fully acceptabl e in this respect. Correspondence with a recent generalization of the Haken-Strobl-Reineker model is found.