The Dynamical Structure Function of the One-Component Plasma Revisited

We present high precision Molecular Dynamics simulations for the dynamical structure function, S (k, ω), of the classical Coulomb One Component Plasma (OCP), for a wide range of the coupling parameter Γ (from 0.05 to 10 000). We follow the positive-to-negative transition of the slope of the ω (k) dispersion curve at small wave numbers caused by the onset of correlations with increasing coupling. The high signal-to-noise ratio of the data over several orders of magnitude allows examination of a wide dynamical range of S (k, ω), including extreme values of ω and k, and the identification of waves at higher harmonics of the plasma frequency. Sum rules are found to be accurately satisfied. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)