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MO: Molekülphysik
MO 19: Poster II (Energietransfer, Reaktionen, Photoionisation, Femtosekundenspektroskopie, ultrakurze Pulse)
MO 19.15: Poster
Thursday, March 7, 2002, 17:30–19:30, Schloss
Numerical simulation of time-resolved absorption/emission spectra of betaine-30 in solution — •I. Kondov1, U. Kleinekathöfer1,2, and M. Schreiber1,2 — 1Institut für Physik, Technische Universität, D-09107 Chemnitz, Germany — 2International University Bremen, D-28725 Bremen, 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. An electron transfer model including two excited states of betaine-30 is considered. The rest of the system is treated as a thermal reservoir. The experimentally detected signal [1] is simulated using the time evolution of the reduced density matrix.
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 by means of a stochastic wave function algorithm designed for unraveling equations which do not have Lindblad structure.
[1] S. A. Kovalenko, N. Eilers-König, T. A. Senyushkina, and N. P. Ernsting, J. Phys. Chem. A 105, 4834 (2001).
[2] U. Kleinekathöfer, I. Kondov, and M. Schreiber, Chem. Phys. 268, 121 (2001).