Atomistic Potential Models for Ionic Liquid Simulations

1 Atomistic Potential Models for Ionic Liquid Simulations 

The ah initio methods can be used in developing approximate classical expressions for the interactions present in these systems. The way in which this is done is the subject of this section. We note in passing that recent work on so-called ab initio molecular dynamics such as Car-Parinello MD [22-24] is blurring the distinction between purely ab initio methods and the classical simulation methods described below. In fact, the first ab initio M D simulation study of an ionic liquid was reported recently [21]. 

The First Ionic Liquid Simulations Alkali Halides 

We will use the shorthand term force field to mean a set of analytic equations that approximate the energetic interactions among atoms in a system. These interactions take many forms, from strong forces characteristic of covalent bonds to weaker forces representative of Van der Waals interactions. The origins of the current force fields used to simulate room temperature ionic liquids can be found in earlier works on alkali halides. The most widely used functional form is that due to the work of Huggins and Mayer [103] 

What can someone interested in room-temperature ionic liquids learn from the results of these alkali halide simulations. First, despite over thirty years of study and the fact that alkali halide salts have a simpler sttucture than ionic liquids it is still difficult to quantitatively predict every thermophysical property of these systems with classical simulations, particularly if one insists on using the same force field for every property. Some properties, such as lattice energies and volumetric 

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