Lennard-Jones Parameters Determined to Reproduce the Solubility of NaCl and KCl in SPC/E, TIP3P, and TIP4P/2005 Water

Abstract

Most classical non-polarizable ion potential models underestimate the solubility values of NaCl and KCl in water significantly. We determine Lennard-Jones (LJ) parameters of Na + , K + , and Clthat reproduce the solubility as well as the hydration free energy in dilute aqueous solutions for three water potential models, SPC/E, TIP3P, and TIP4P/2005. The ion-oxygen distance in the solution and the cation-anion distance in salt are also considered in the parametrization. In addition to the target properties, the hydration enthalpy, hydration entropy, self-diffusion coefficient, coordination number, lattice energy, enthalpy of solution, density, viscosity, and number of contact ion pairs are calculated for comparison with 17 frequently used or recently developed ion potential models. The overall performance of each ion model is represented by a global score using a scheme that was originally developed for comparison of water potential models. The global score is better for our models than for the other 17 models not only because of the quite good prediction for the solubility but also because of the relatively small deviation from the experimental value for many of the other properties.

Molecular Simulations of Electrotunable Lubrication: Viscosity and Wall Slip in Aqueous Electrolytes

“…We use the SPC/E water model [40], which we chose over the conceptually identical TIP3P model [45] because the latter strongly underestimates solubility of NaCl [46,47]. Water molecules are kept rigid using the RATTLE algorithm [48].…”

Salt-Water System under Diamond Confinement

“…We used the non-polarizable force-field developed by Yagasaki et al . to model NaCl, which we refer to as the TMH force field henceforth.…”

“…to model NaCl, which we refer to as the TMH force field henceforth. The TMH model has been reported to generate more accurate values of ion–oxygen distance, hydration free energy, cation–anion distance in salt, and the solubility, compared to 17 other commonly used models . For the carbon–oxygen interactions, we have used parameters from Werder et al, which accurately reproduce the contact angle of water on graphite.…”

Theory of electrolytes including steric, attractive, and hydration interactions

“…In this instability, the ions aggregate as solvophobic spinodal decomposition 30,60,114 . However, ion association can trigger precipitate formation in metastable solutions, which is the case for alkali halide salts in water [115][116][117] . For LiF, its solubility (= 0.14 mol/L = 0.002n w ) is exceptionally small (≪ n spi s ).…”

“…In molecular dynamics simulation of aqueous electrolytes [115][116][117] , the pair potentials among ions and water molecules depend on the ion species.…”