Debye-Hückel (DH) theory is extended to treat two-component size- and charge-asymmetric primitive models, focusing primarily on the 1:1 additive hard-sphere electrolyte with, say, negative ion diameters a(--) larger than the positive ion diameters a(++). The treatment highlights the crucial importance of the charge-unbalanced "border zones" around each ion into which other ions of only one spec...

This work discusses the introduction of concentration dependency relative permittivity in context activity coefficient models at different stages derivation models. We evaluate an experimental correlation and Michelsen–Mollerup–Breil model for order to assess impact using these both Debye–Hückel Born equations. Our results show that effects introducing levels are significant quantitative. Using...

A comprehensive mixed-solvent electrolyte model has been applied to calculate phase equilibria and other thermodynamic properties of multicomponent solutions containing salts, acids and bases in wide concentration ranges. The model combines an excess Gibbs energy model with detailed speciation calculations. The excess Gibbs energy model consists of a long-range interaction contribution represen...

It has been argued that for a finite two-dimensional classical Coulomb system of characteristic size R, in its conducting phase, as R → ∞ the total free energy (times the inverse temperature β) admits an expansion of the form: βF = AR +BR+ 1 6 χ lnR, where χ is the Euler characteristic of the manifold where the system lives. The first two terms represent the bulk free energy and the surface fre...

A Toy Model of an artificial chemistry that treats molecules as graphs was implemented based on a simple Extended Hückel Theory method. Here we describe an extension of the model that models chemical reactions as the result of “collisions”. In order to avoid a possible bias arising from prescribed generic reaction mechamisms, the reactions are simulated in a way that treats the formation and br...

A diffuse interface (phase field) model for an electrochemical system is developed. We describe the minimal set of components needed to model an electrochemical interface and present a variational derivation of the governing equations. With a simple set of assumptions: mass and volume constraints, Poisson's equation, ideal solution thermodynamics in the bulk, and a simple description of the com...

On the basis of a hydrodynamical model analogous to that in critical fluids, we investigate the influences of shear flow upon the electrostatic contribution to the viscosity of binary electrolyte solutions in the Debye-Hückel approximation. Within the linear-response theory, we reproduce the classical limiting law that the excess viscosity is proportional to the square root of the concentration...

A middle-resolution coarse-grained model of DNA is proposed. The DNA chain is built of spherical and planar rigid bodies connected by elastic virtual bonds. The bonded part of the potential energy function is fit to potentials of mean force of model systems. The rigid bodies are sets of neutral, charged, and dipolar beads. Electrostatic and van der Waals interactions are parametrized by our rec...

Pharmacophore models play an essential role in drug discovery. Generating pharmacophore models which encode accurate molecular recognition features are highly dependent on properly defined annotations. Simplistic or ill-defined pharmacophore annotations which do not capture subtle electronic or geometric effects lead to many inaccuracies. SMARTS patterns which are often used to specify annotati...

A theoretical analysis of Coulomb systems on lattices in general dimensions is presented. The thermodynamics is developed using Debye–Hückel theory with ion-pairing and dipole–ion solvation, specific calculations being performed for three-dimensional lattices. As for continuum electrolytes, low-density results for simple cubic ~sc!, body-centered cubic ~bcc!, and face-centered cubic ~fcc! latti...