  Bulk properties of equilibrium liquids are a manifestation of intermolecular
forces. Here, we show how these forces imprint on dynamical fluctuations in the
Lyapunov exponents for simple fluids with and without attractive forces. While
the bulk of the spectrum is strongly self-averaging, the first Lyapunov
exponent self-averages only weakly and at a rate that depends on the length
scale of the intermolecular forces; short-range repulsive forces quantitatively
dominate longer range attractive forces, which act as a weak perturbation that
slows the convergence to the thermodynamic limit. Regardless of intermolecular
forces, the fluctuations in the Kolmogorov-Sinai entropy rate diverge, as one
expects for an extensive quantity, and the spontaneous fluctuations of these
dynamical observables obey fluctuation-dissipation like relationships.
Together, these results are a representation of the van der Waals picture of
fluids and another lens through which we can view the liquid state.
