TY - JOUR

T1 - Structural similarity of an ionic liquid and the mixture of the neutral molecules

AU - Shelepova, Ekaterina A.

AU - Ludwig, Ralf

AU - Paschek, Dietmar

AU - Medvedev, Nikolai N.

N1 - Funding Information: Financial support from grants RFBR (No. 18-03-00045 ) is gratefully acknowledged. Funding Information: This work has been supported by the Deutsche Forschungsgemeinschaft (DFG) within the projects LU 506/14-2 and LU 506/15-1 . Publisher Copyright: © 2021 Elsevier B.V. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/5/1

Y1 - 2021/5/1

N2 - Using coarse-grained molecular dynamics simulations we present a comparison between the structure of an ionic liquid (IL) and its neutral counterpart (a mixture of the same molecules at the same density, but without charges). We show that there is a surprising structural similarity between the two studied systems with respect to the packing of the molecules, regardless of the fact that the arrangement of anions and cations in the ionic liquid differs significantly from the arrangement of their analogues in the neutral mixture. Rather similar behavior was obtained for the computed total (all-grain) radial distribution functions of the entire systems, as well as for the sizes and shapes of the local voids defined by Delaunay simplices. This structural similarity was also observed for an IL with a modified charge distribution on the cations, and for an uncharged Lennard-Jones liquid, both at the same density. We would like to emphasize that the overall structure of a dense disordered molecular system is determined, above all, by the impenetrability of atoms, i.e. by the geometric laws of atomic packings.

AB - Using coarse-grained molecular dynamics simulations we present a comparison between the structure of an ionic liquid (IL) and its neutral counterpart (a mixture of the same molecules at the same density, but without charges). We show that there is a surprising structural similarity between the two studied systems with respect to the packing of the molecules, regardless of the fact that the arrangement of anions and cations in the ionic liquid differs significantly from the arrangement of their analogues in the neutral mixture. Rather similar behavior was obtained for the computed total (all-grain) radial distribution functions of the entire systems, as well as for the sizes and shapes of the local voids defined by Delaunay simplices. This structural similarity was also observed for an IL with a modified charge distribution on the cations, and for an uncharged Lennard-Jones liquid, both at the same density. We would like to emphasize that the overall structure of a dense disordered molecular system is determined, above all, by the impenetrability of atoms, i.e. by the geometric laws of atomic packings.

KW - Coarse grained models

KW - Ionic liquids

KW - Liquid structure

KW - Molecular dynamics simulation

KW - Voronoi-Delaunay tessellation

UR - http://www.scopus.com/inward/record.url?scp=85101290494&partnerID=8YFLogxK

U2 - 10.1016/j.molliq.2021.115589

DO - 10.1016/j.molliq.2021.115589

M3 - Article

AN - SCOPUS:85101290494

VL - 329

JO - Journal of Molecular Liquids

JF - Journal of Molecular Liquids

SN - 0167-7322

M1 - 115589

ER -