Practical Considerations for Finite Concentrations Molecular Dynamics Simulations
Abstract
Understanding concentrated electrolytes requires a theory that spans local hydration and mesoscale interfacial assembly. We present an integrated workflow-SCOPE-that combines (i) enhanced sampling focused on a single Li+ ion, (ii) reweighting of biased trajectories to recover equilibrium microstate probabilities, and (iii) a chemical-potential correction that accounts for the limited reservoir of free water in finite simulation boxes. Applied to LiCl(aq) across 0.5-26 M and 283-313 K, this approach reveals a simple organizing principle: solvated ions dominate at low concentration; contact ion pairs emerge at intermediate strength; and aggregated Li-xCl clusters become most stable at the solubility limit. The resulting free-energy trends predict temperature-dependent solubility in close agreement with experiment and clarify the role of interfacial nucleation in precipitation. Beyond the simple LiCl(aq) salt considered here, SCOPE offers a transferable strategy for characterizing speciation and phase behavior in concentrated liquid systems where collective coordinates and rare events dominate.
Cite
@article{arxiv.2601.17244,
title = {Practical Considerations for Finite Concentrations Molecular Dynamics Simulations},
author = {Xiaoxu Ruan and Fabrice Roncoroni and David Prendergast and Tod A Pascal},
journal= {arXiv preprint arXiv:2601.17244},
year = {2026}
}
Comments
19 pages, 6 figures