TY  - JOUR
AU  - Lesch, Volker
AU  - Montes-Campos, Hadrián
AU  - Méndez-Morales, Trinidad
AU  - Gallego, Luis Javier
AU  - Heuer, Andreas
AU  - Schröder, Christian
AU  - Varela, Luis M.
TI  - Molecular dynamics analysis of the effect of electronic polarization on the structure and single-particle dynamics of mixtures of ionic liquids and lithium salts
JO  - The journal of chemical physics
VL  - 145
IS  - 20
SN  - 1089-7690
CY  - Melville, NY
PB  - American Institute of Physics
M1  - FZJ-2017-07603
SP  - 204507 -
PY  - 2016
AB  - We report a molecular dynamics study on the effect of electronic polarization on the structure and single-particle dynamics of mixtures of the aprotic ionic liquid 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide ([EMIM][TFSI]) doped with a lithium salt with the same anion at 298 K and 1 bar. In particular, we analyze the effect of electron density fluctuations on radial distribution functions, velocity autocorrelation functions, cage correlation functions, mean-squared displacements, and vibrational densities of states, comparing the predictions of the quantum-chemistry-based Atomistic Polarizable Potential for Liquids, Electrolytes, & Polymers (APPLE&P) with those of its nonpolarizable version and those of the standard non-polarizable Optimized Potentials for Liquid Simulations-All Atom (OPLS-AA). We found that the structure of the mixture is scarcely modified by the fluctuations in electron charge of their constituents, but their transport properties are indeed quite drastically changed, with larger mobilities being predicted for the different species in the bulk mixtures with the polarizable force field. Specifically, the mean-squared displacements are larger for the polarizable potentials at identical time intervals and the intermediate subdiffusive plateaus are greatly reduced, so the transition to the diffusive regime takes place much earlier than in the non-polarizable media. Moreover, the correlations of the added cations inside their cages are weakened out earlier and their vibrational densities of states are slightly red-shifted, reflecting the weakening effect of the electronic polarization on the Coulomb coupling in these dense ionic media. The comparison of OPLS-AA with non-polarizable APPLE&P indicates that adding polarization to OPLS-AA is not sufficient to achieve results close to experiments.
LB  - PUB:(DE-HGF)16
C6  - pmid:27908097
UR  - <Go to ISI:>//WOS:000390118200034
DO  - DOI:10.1063/1.4968393
UR  - https://juser.fz-juelich.de/record/840037
ER  -