Simulating Monovalent and Divalent Ions in Aqueous Solution Using a Drude Polarizable Force Field

摘要

An accurate representation of ion solvation in aqueous solution is critical for meaningful computer simulations of a broad range of physical and biological processes. Polarizable models based on classical Drude oscillators are introduced and parametrized for a large set of monatomic ions including cations of the alkali metals (Li~+, Na~+, K~+, Rb~+, and Cs~+) and alkaline earth elements (Mg~(2+), Ca~(2+), Sr~(2+), and Ba~(2+)) along with Zn~(2+) and halide anions (F~-, CI~-, Br, and I~-). The models are parametrized, in conjunction with the polarizable SWM4-NDP water model [Lamoureux et al. Chem, Phys. Lett. 2006, 418, 245], to be consistent with a wide assortment of experimentally measured aqueous bulk thermodynamic properties and the energetics of small ion-water clusters. Structural and dynamic properties of the resulting ion models in aqueous solutions at infinite dilution are presented.