Probing Spatial Locality in Ionic Liquids with the Grand Canonical Adaptive Resolution Molecular Dynamics Technique

Abstract: We employ the Grand Canonical Adaptive Resolution Molecular Dynamics Technique (GC-AdResS) to test the spatial locality of the 1-ethyl 3-methyl imidazolium chloride liquid. In GC-AdResS atomistic details are kept only in an open sub-region of the system while the environment is treated at coarse-grained level, thus if spatial quantities calculated in such a sub-region agree with the equivalent quantities calculated in a full atomistic simulation then the atomistic degrees of freedom outside the sub-region play a negligible role. The size of the sub-region fixes the degree of spatial locality of a certain quantity. We show that even for sub-regions whose radius corresponds to the size of a few molecules, spatial properties are reasonably {reproduced} thus suggesting a higher degree of spatial locality, a hypothesis put forward also by other {researchers} and that seems to play an important role for the characterization of fundamental properties of a large class of ionic liquids.