A molecular contact theory for simulating polarization: application to dielectric constant prediction

Abstract

Contacts between molecular surfaces give good insight to local polarization and predict dielectric constant for both pure liquids and binary mixtures with ∼20% error, leading to new perspectives of efficient rationalization of electrolyte solutions.

On the analogy between the restricted primitive model and capacitor circuits. Part II: A generalized Gibbs-Duhem consistent extension of the Pitzer-Debye-Hückel term with corrections for low and variable relative permittivity

“…Furthermore, dielectric decrement data for both salt and ionic liquid systems is scarce, highly variable and controversial 69,89 and the modelling of the relative permittivity of highly polar solvents without ions is already a challenging topic. 111 Interestingly, modified mixing rules like equation (31) and others applied in the literature 8, 16,18,68 seem to offer a rough, but acceptable general approach to this problem as long as precision in the modelling of 𝜀 𝑚 is not a priority and additional parameters in a model are able to counterbalance systematic deviations. One must stress the fact that combining long-range electrostatics as previously described with a predictive model like COSMO-RS-ES will challenge the capabilities of the shortrange model to describe qualitative trends.…”

Nonrotational Mechanism of Polarization in Alcohols

“…27 Accounting for intermolecular correlations and local-field effects 28−30 by introducing, for instance, the Kirkwood g-factor and using improved models for the relaxation time 31−33 yield good theory−experiment agreement for the dielectric constants of alcohols. 18,34 dynamical processes, such as self-diffusion, protonic current, and high-frequency (terahertz) modes as well as their temperature dependencies, still lack clarity. 12,35−38 As an alternative, one may consider a chain-like structure made of several −OH groups as the transient chain model for monohydric alcohols.…”

“…In addition, the Debye model does not account for steric and entropic effects that influence the molecules’ geometry as shown with isomeric octanols . Accounting for intermolecular correlations and local-field effects − by introducing, for instance, the Kirkwood g -factor and using improved models for the relaxation time − yield good theory–experiment agreement for the dielectric constants of alcohols. , However, other dynamical processes, such as self-diffusion, protonic current, and high-frequency (terahertz) modes as well as their temperature dependencies, still lack clarity. ,− …”

Non-rotational mechanism of polarization in alcohols

“…Accounting for intermolecular correlations and localfield effects [29][30][31], and using improved models for the relaxation time [32][33][34] yields good theory-experiment agreement for the dielectric constants of alcohols [18,35]. However, other dynamical processes, such as selfdiffusion, protonic current, and high-frequency (terahertz) modes as well as their temperature dependen-cies, still lack clarity [12,[36][37][38][39] because the atomic and molecular dynamics, their time-dependent correlations, and relations between conductivity and mobility are all hidden in the dielectric response.…”