Simple analysis of the thermodynamic properties of the one-component plasma

Abstract

The one-component plasma model describing a fluid of identically charged point-like ions moving in a uniform continuum background charge density neutralizing the total system is a chemically relevant special case of the primitive models used in theories of electrolyte solutions. It poses, due to its lack of hard-sphere repulsion, an unusual and particularly difficult problem for both the traditional Debye—H u ckel theory and the modern pair correlation theories. We show that the gross error of the Debye—H u ckel predictions for thermodynamic properties at high coupling strength (as compared to Monte Carlo simulation results) can be effectively removed by an extremely simple modification of the theory based on the recognition that the exponential particle density must be truncated close to the ion so as not to become negative.