We present an analysis of the dynamics of ion-pairing of Lithium Fluoride (LiF) in aqueous
solvent using both detailed molecular simulation as well as reduced models within a Generalized
Langevin Equation (GLE) framework. We explored the sensitivity of the ion-pairing
phenomena to the details of descriptions of molecular interaction, comparing two empirical
potentials to explicit quantum based density functional theory. We find quantitative differences
in the potentials of mean force for ion-pairing as well as time dependent frictions that lead to
variations in the rate constant and reactive flux correlation functions. These details reflect
differences in solvent response to ion-pairing between different representations of molecular
interaction and influence anharmonicity of the dynamic response. We find that the short time
anharmonic response is recovered with a GLE parameterization. Recovery of the details of
long time response may require extensions to the reduced model. We show that the utility of
using a reduced model leads to a straight forward application of variational transition state theory
concepts to the condensed phase system. The significance of this is reflected in the analysis
of committor distributions and the variation of planar hypersurfaces, leading to an improved
understanding of factors that determine the rate of LiF ion-pairing.