Abstract
In this work, we computed electrical conductivities under ambient conditions of aqueous NaCl and KCl solutions by using the EinsteinHelfand equation. Common force fields (charge q = ±1 e) do not reproduce the experimental values of electrical conductivities, viscosities, and diffusion coefficients. Recently, we proposed the idea of using different charges to describe the potential energy surface (PES) and the dipole moment surface (DMS). In this work, we implement this concept. The equilibrium trajectories required to evaluate electrical conductivities (within linear response theory) were obtained by using scaled charges (with the value q = ±0.75 e) to describe the PES. The potential parameters were those of the MadridTransport force field, which accurately describe viscosities and diffusion coefficients of these ionic solutions. However, integer charges were used to compute the conductivities (thus describing the DMS). The basic idea is that although the scaled charge describes the ionwater interaction better, the integer charge reflects the value of the charge that is transported due to the electric field. The agreement obtained with experiments is excellent, as for the first time electrical conductivities (and the other transport properties) of NaCl and KCl electrolyte solutions are described with high accuracy for the whole concentration range up to their solubility limit. Finally, we propose an easy way to obtain a rough estimate of the actual electrical conductivity of the potential model under consideration using the approximate NernstEinstein equation, which neglects correlations between different ions.
Original language  English 

Pages (fromto)  53805393 
Journal  Journal of chemical theory and computation 
Volume  19 
Issue number  16 
DOIs  
Publication status  Published  2023 
Fingerprint
Dive into the research topics of 'Computation of Electrical Conductivities of Aqueous Electrolyte Solutions: Two Surfaces, One Property'. Together they form a unique fingerprint.Datasets

Sample simulation files underlying the publication: Computation of Electrical Conductivities of Aqueous Electrolyte Solutions: Two Surfaces, One Property
Blazquez, S. (Creator), Abascal, J. L. F. (Creator), Lagerweij, J. (Creator), Habibi, P. (Creator), Dey, P. (Creator), Vlugt, T. J. H. (Creator), Moultos, O. (Creator) & Vega, C. (Creator), TU Delft  4TU.ResearchData, 24 Aug 2023
DOI: 10.4121/B9260A5E8A114EFD822AE244E0F7798B
Dataset/Software: Dataset