  Liquids in equilibrium exhibit two types of disorder, simple and complex.
Typical simple disorder liquid are liquid nitrogen, or weakly polar liquids.
Complex liquids concern those who can form long lived local assemblies, and
cover a large range from water to soft matter and biological liquids. The
existence of such structures leaves characteric features upon the atom-atom
correlation functions, concerning both atoms which directly participate to
these structure and those who do not. The question we ask here is: does these
features have also characteristic dynamical aspects, which could be tracked
through dynamical correlation functions. Herein, we compare the van Hove
function, intermediate scattering function and the dynamical structure factor,
for both types of liquids, using force field models and computer simulations.
The calculations reveal the paradoxical fact that neighbouring atom
correlations for simple disorder liquids relax slower than that for complex
disorder liquids, while prepeak features typical of complex disorder liquids
relax even slower. This is an indication of the existence of fast kinetic
self-assembly processes in complex disorder liquids, while the lifetime of such
assemblies itself is quite slow. This is further confirmed by the existence of
a very low-k dynamical pre-peak uncovered in the case of water and ethanol.
