Spatial distribution function (SDF) is an extension of RDF to the three dimensions of space. For system B, the obtained results are rather similar to those of system A. With increasing carbonate content (system C and system D), however, it seems that the large amount of carbonate disturbs the original near ordering which is found in the pure ionic liquid. For system B, the obtained results are rather similar to those of system A. With increasing carbonate content (system C and system D), 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 with increasing carbonate concentration.