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Ion-ion correlations: an improved one-component plasma correction

Marcia C. Barbosa·Markus Deserno·Christian Holm
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Abstract

Based on a Debye-Hueckel approach to the one-component plasma we propose a new free energy for incorporating ionic correlations into Poisson-Boltzmann like theories. Its derivation employs the exclusion of the charged background in the vicinity of the central ion, thereby yielding a thermodynamically stable free energy density, applicable within a local density approximation. This is an improvement over the existing Debye-Hueckel plus hole theory, which in this situation suffers from a "structuring catastrophe". For the simple example of a strongly charged stiff rod surrounded by its counterions we demonstrate that the Poisson-Boltzmann free energy functional augmented by our new correction accounts for the correlations present in this system when compared to molecular dynamics simulations.

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Marcia C. Barbosa, Markus Deserno, Christian Holm. 1999-10-22. Ion-ion correlations: an improved one-component plasma correction. https://doi.org/10.1209/epl%2Fi2000-00407-y

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