Electrolytes at charged interfaces: Ion–ion–interface three-body correlation functions

Abstract

Inhomogeneous correlation functions for model " soft Ï 2È2 and 1È1 electrolytes at a charged interface have been determined by the soÈcalled " pair Ï approximation of integral equation theory. The solvent is modeled as a structureless dielectric continuum at 25 ¡C. The wallÈionÈion structure is calculated using the inhomogeneous OrnsteinÈZernike relation, together with the hypernetted chain closure, and one of two choices for the functional relationship between the singlet and pair correlation functions. Both the interfacial density proÐles and the inhomogeneous pair correlation functions are calculated. For most cases, the inhomogeneous pair correlation functions near the interface vary signiÐcantly from the homogeneous pair correlation functions. This deviation generally becomes stronger as the charge on the surface increases, and the deviation generally extends out further from the interface as the surface charge increases. The density proÐles predicted by the pair approximations generally show less structure than the singlet approximation density proÐles, whereas the inhomogeneous pair correlation functions generally predict more structure than would be expected by simply assuming bulk pair correlation functions. The density proÐles and inhomogeneous correlation functions are also found to agree qualitatively with previous simulations which used " charged hardÈsphere/charged hardÈwall Ï potentials.

Multiscale analytic continuation approach to nanosystem simulation: Applications to virus electrostatics

“…This phenomenology describes a smooth transition in ion accessibility from 0 to 1 is suggested in other studies, [44][45][46][47][48] the basis of which is fluctuating positions of the fixed and mobile ions, as well as the continuous profile of electron density around a given ion. The mean displacement of an ion from an equilibrium position was considered to be Ͼ0.1͑a i + b l ͒ Å.…”

“…However, negligible tight binding is expected under conditions chosen for the comparison ͑a relatively low stationary charge density and 1:1 electrolyte͒. 47 Our software can be implemented for nonzero surface boundary conditions with minimal alteration. To magnify differences, the potential profiles in Fig.…”