Charge oscillations in Debye-Hückel theory

¹ Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
² Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA

Received: 10 June 1997
Accepted: 11 August 1997

Abstract

The recent generalized Debye-Hückel (GDH) theory is applied to the calculation of the charge-charge correlation function, . The resulting expression satisfies both i) the charge neutrality condition and ii) the Stillinger-Lovett second-moment condition for all T and , the overall ion density, and iii) exhibits charge oscillations for densities above a “Kirkwood line” in the -plane. This corrects the normally assumed DH charge correlations, and, when combined with the GDH analysis of the density correlations, leaves the GDH theory as the only complete description of ionic correlation functions, as judged by i)–iii), iv) exact low-density variation, and v) reasonable behavior near criticality.