Ab Initio Molecular Dynamics Simulation of a Room Temperature Ionic Liquid

Ab initio molecular dynamics simulations have been performed for the first time on the room-temperature
organic ionic liquid dimethyl imidazolium chloride [DMIM][Cl] using density functional theory. The aim is
to compare the local liquid structure with both that obtained from two different classical force fields and
from neutron scattering experiments. The local structure around the cation shows significant differences
compared to both the classical calculations and the neutron results. In particular, and unlike in the gas-phase
ion pair, chloride ions tend to be located near a ring C−H proton in a position suggesting hydrogen bonding.
The results are used to suggest ways in which the classical potentials may be improved.