The liquid phase structure was studied for each system in terms of spatial distribution functions (SDFs). SDFs provide an extension of radial distribution functions to the three dimensions of space. The SDFs were built and analyzed with the TRAVIS program [TFSI] ion pairs, and this finding is in agreement with other reported studies where, in the C 1 -protonated imidazolium cations, the H 1 atom is the most favorable interaction site between cations and anions . Distributions around H 4 and H 5 atoms were found with lower probabilities For system F 1 , the obtained results are rather similar to those of system G 1 . With increasing carbonate content (system E 1 and system D 1 ), however, it seems that the large amount of carbonate disturbs the original near ordering which is found in the pure ionic liquid. The H 1 atom of the N 1 -C 1 -N 2 plane is less populated with [TFSI] -anions because of the possible competition of EC/DMC with increasing carbonate concentration. This result is substantiated by the RDF based results as shown in in