  The intermolecular interactions in the title compound are investigated using
self-consistent charge density functional based tight binding molecular
dynamics. Emphasis is put on the analysis of correlated motions of ion pairs
using ideas of network theory. At equilibrium such correlations are not very
pronounced on average. However, there exist sizeable local correlations for
cases where two cations share the same anion via two NHO-hydrogen bonds. The
effect of an external perturbation, which artificially introduces a sudden
local heating of an NH-bond, is investigated using nonequilibrium molecular
dynamics. Here, it is found that the average N-H bond vibrational relaxation
time is about 5.3 ~ps. This energy redistribution is rather nonspecific with
respect to the ion pairs and does not lead to long-range correlations spreading
from the initially excited ion pair.
