Nevertheless, ongoing from pure ILs to IL mixtures, there is an obvious increase in complexity arising from the presence of more ions. Therefore, molecular investigations on IL mixtures are often more difficult than pure ILs. The theoretical and experimental investigations on IL mixtures are often difficult in comparison with pure ILs. Hence, the progress of designing and utilizing the IL mixtures with more extraordinary properties will depend on advancing an in-depth understanding of their physical and chemical properties as well as the interactions between different cations and anions. At present, there have been a number of previous experimental studies on thermodynamic and transport properties of imidazoliumbased IL mixtures . It is particularly important to understand how the structural properties of IL mixtures change upon mixing, as well as the dependence of the properties of the resulting mixtures on their composition. The properties of IL mixtures arise from different cation-anion, cation-cation, and anion-anion interactions, including Coulomb, van der Waals as well as hydrogen bond interactions. . For example, a major finding of recent experimental studies reveals that the structure of IL mixtures is mainly determined by the random distribution of ions driven by Coulomb interaction . Due to the limited number of experimental studies on such interaction mechanisms, little is known on the origins of the thermodynamic and transport properties of imidazolium based IL mixtures. To date, molecular dynamics (MD) simulations in combination with experimental approaches have provided good insight into the structure and dynamics of ILs . Because of higher accuracy, ab initio molecular dynamics (AIMD) simulations may add valuable insight into the structures of solvation shells of ionic salts in a variety of organic solvents, but they require relatively higher computational demands. Due to the limited time-and size-scales of DFT methods, and high cost of AIMD simulations, classical molecular dynamics (CMD) has largely been the method of choice for investigations of IL structure . Early imidazolium based ionic liquid force fields by the groups of Maginn , Berne and Stassen helped shape initial thoughts as to the origin of their unique solvent properties.