HYDRODYNAMIC CALCULATION OF THE FREQUENCY-DEPENDENT FRICTION ON THE BOND OF A DIATOMIC MOLECULE

In this paper molecular hydrodynamics is used to calculate the dynamic friction on the intramolecular vibrational coordinate of a homonuclea r diatomic molecule dissolved in a simple liquid. The predicted dynami c friction is then compared to recent computer experiments. Agreement with the experimental dynamic function is obtained when the linearized hydrodynamics is modified to include Gaussian viscoelasticity and com pressibility. The hydrodynamic friction on the bond appears to agree q ualitatively very well, although quantitative agreement is not found a t high frequencies. Various limits of the hydrodynamic friction are di scussed. (C) 1995 American Institute of Physics.