Berlin 2001 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 17: Poster: Spectroscopy and Single Particle Spectroscopy of Molecular Systems, Photoprocesses, Biological Systems

CPP 17.26: Poster

Tuesday, April 3, 2001, 12:30–15:00, AT1

Theory and numerical studies of electron transfer in betaine-30 — •I. Kondov, U. Kleinekathöfer, and M. Schreiber — Institut für Physik, Technische Universität, D-09107 Chemnitz, Germany

Applying the Redfield theory the electron back-transfer reaction in betaine-30 in liquid environment can be simulated quantitatively. The new model effectively substitutes the vibronically coupled molecular normal modes as well as the solvent modes by a treatably small set of reaction coordinates. Earlier calculations [1] involved only a single effective reaction coordinate. The rest of the system is treated as a thermal reservoir. The experimentally detected time-resolved spectra, such as time-resolved absorption, are simulated using the time evolution of the reduced density matrix.

In the simulation the specific features of the pulse sequence are taken into account. The correct long-time dynamics and especially approaching of the thermal equilibrium are achieved by an exact treatment of the intercenter coupling in the system-bath interaction [2]. This is done in the basis of eigenstates of the vibronic Hamiltonian. The equation of motion for the reduced density matrix is solved numerically either by means of density matrix propagators [3] or stochastic wave function methods.

[1] C. Fuchs and M. Schreiber, J. Chem. Phys. 105, 1023 (1996).

[2] U. Kleinekathöfer, I. Kondov and M. Schreiber, Chem. Phys. (submitted; physics/0012012).

[3] I. Kondov, U. Kleinekathöfer and M. Schreiber, J. Chem. Phys. (in press; physics/0009059).