Polar solvation dynamics: A combination of the reference interaction-site
model and mode-coupling theories
K. Nishiyama, T. Yamaguchi, F. Hirata, and T. Okada
Venture Business Laboratory, Osaka University, Suita,
Osaka 565-0871, Japan;
Department of Molecular Design and Engineering,Graduate School of Engineering,
Nagoya University, Chikusa, Nagoya, Aichi 464-8603, Japan;
Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan;
Department of Chemistry, Graduate School of Engineering Science, Osaka
University, Toyonaka, Osaka 560-8531, Japan
Abstract:
We employ the reference interaction-site model (RISM) theory for solvation
dynamics of simple ions in acetonitrile. For the description of time
evolution of solvent relaxation, we apply the mode-coupling theory recently
developed by Yamaguchi and coworkers [Mol. Phys. 101,
1211 (2003)]. The combination of the RISM/mode-coupling theory is used
for the calculation of the dynamic response function, SS(t),
which measures the relaxation of average energy of the solute-solvent
system. SS(t) decays with the Gaussian plus underdamped
curves in the time duration of first 1 ps, followed by slow, long-tailed
components down to tens of picoseconds. We show that the RISM/mode-coupling
framework is applicable rather well for the detailed description of
solvation dynamics at the molecular level.
*Lecture presented at the European Molecular Liquids
Group (EMLG) Annual Meeting on the Physical Chemistry of Liquids: Novel
Approaches to the Structure, Dynamics of Liquids: Experiments, Theories,
and Simulation,Rhodes, Greece, 7-15 September 2002. Other presentations
are published in this issue, pp. 1-261.
