Scientific Achievement
We demonstrate that a computationally inexpensive modification non-polarizable force fields: charge renormalization, can harmonize computed and experimentally determined structure and dynamic attributes of nonaqueous electrolytes. It is sufficient to reproduce dynamics over range of 0-2 M salt while not sacrificing quality of structural properties.
Significance and Impact
Traditional force fields for nonaqueous electrolyte solutions focused mainly on the short-range properties (e.g., coordination numbers for ions). Consequently, the dynamic properties of these solutions or the clustering of the associated ions on a long timescale cannot be reproduced accurately. As these properties are important for practical applications, closer evaluations of force fields are required before in silico design of electrolytes becomes a reliable tool for prediction, and our charge renormalization method is useful in this regard.
Research Detail
- Performed MD simulations using four force field parameters sets from quantum chemistry calculations and charge renormalization
- Dramatically different ionic dynamics and consistent solution structures calculated from MD indicate inadequate representation of long-range interactions
- Comparisons with experiments (neutron scattering, NMR, conductivity) reveal that charge renormalization recovered dynamics while holding the structure
