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Updated: May 28, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Vibrational energy transfer and anisotropy decay in liquid water: is the Förster model valid?
Mino Yang1, Fu Li, J L Skinner
1Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea.
Abstract:
Ultrafast pump-probe anisotropy experiments have been performed on liquid H(2)O and D(2)O. In both cases, the anisotropy decay is extremely fast (on the order of 100 or 200 fs) and is presumed due to resonant vibrational energy transfer. The experiments have been interpreted in terms of the Förster theory, wherein the rate constant for intermolecular hopping transport is proportional to the inverse sixth power of the distance between the vibrational chromophores. In particular, the anisotropy decay is assumed to be simply related to the survival probability as calculated with the Förster theory. While the theory fits the data well, and is a reasonable model for these systems, there are several assumptions in the theory that might be suspect for water. Using our mixed quantum/classical model for vibrational spectroscopy and dynamics in liquid water, which agrees well with anisotropy decay experiments on the pure liquids as well as H(2)O/D(2)O mixtures, we critically analyze both the survival probability and anisotropy decay, in order to assess the applicability of the Förster theory.
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