Importance of van der Waals effects on the hydration of metal ions from the Hofmeister series

Liying Zhou; Jianhang Xu; Limei Xu; Xifan Wu

doi:10.1063/1.5086939

Importance of van der Waals effects on the hydration of metal ions from the Hofmeister series

J Chem Phys. 2019 Mar 28;150(12):124505. doi: 10.1063/1.5086939.

Authors

Liying Zhou¹, Jianhang Xu², Limei Xu¹, Xifan Wu²

Affiliations

¹ International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China.
² Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA.

PMID: 30927898
DOI: 10.1063/1.5086939

Abstract

The van der Waals (vdW) interaction plays a crucial role in the description of liquid water. Based on ab initio molecular dynamics simulations, including the non-local and fully self-consistent density-dependent implementation of the Tkatchenko-Scheffler dispersion correction, we systematically studied the aqueous solutions of metal ions (K⁺, Na⁺, and Ca²⁺) from the Hofmeister series. Similar to liquid water, the vdW interactions strengthen the attractions among water molecules in the long-range, leading to the hydrogen bond networks softened in all the ion solutions. However, the degree that the hydration structure is revised by the vdW interactions is distinct for different ions, depending on the strength of short-range interactions between the hydrated ion and surrounding water molecules. Such revisions by the vdW interactions are important for the understanding of biological functionalities of ion channels.