Related Experiment Video
Updated: Apr 20, 2026

Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
Surface affinity of the hydronium ion: the effective fragment potential and umbrella sampling
Kurt R Brorsen1, Spencer R Pruitt, Mark S Gordon
1Ames Laboratory, US-DOE and Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.
Abstract:
The surface affinity of the hydronium ion in water is investigated with umbrella sampling and classical molecular dynamics simulations, in which the system is described with the effective fragment potential (EFP). The solvated hydronium ion is also explored using second order perturbation theory for the hydronium ion and the empirical TIP5P potential for the waters. Umbrella sampling is used to analyze the surface affinity of the hydronium ion, varying the number of solvent water molecules from 32 to 256. Umbrella sampling with the EFP method predicts the hydronium ion to most probably lie about halfway between the center and edge of the water cluster, independent of the cluster size. Umbrella sampling using MP2 for the hydronium ion and TIP5P for the solvating waters predicts that the solvated proton most probably lies about 0.5-2.0 Å from the edge of the water cluster independent of the cluster size.
Related Concept Videos
Polyprotic Acids
Weak Acid Solutions
Precipitation of Ions
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:
Strong Acid and Base Solutions
Water: A Bronsted-Lowry Acid and Base
pH Scale

