Force Fields for Modeling of Ionic Liquids

The objective of this proposal is to develop and validate a methodology for obtaining accurate, reliable and transferable force fields for a variety of ionic liquids (ILs) including those designed for lubrication, gas generation, energy storage and as energetic materials. The methodology involves development of a hierarchy of force fields through reduction of degrees of freedom in a statistical mechanically rigorous way incorporating the influence and effects of important but computationally expensive interactions (e.g., many-body polarization) via systematically parameterized, computationally less expensive representations. Atomistic polarizable force fields will serve as the foundation for the development of this hierarchy of force fields. These force fields are computationally the most expensive but are also the most transferable and accurate. Less expensive two-body nonpolarizable force fields with various levels of coarse-graining (reduction in the number of atomic degrees of freedom) will be parameterized by requiring these potentials to reproduce as accurately as possible the structure, thermodynamics and, if possible, transport properties of various ILs obtained from simulations performed with more detailed transferable potentials.