Coherent molecular motion in aquatic environment. Extraction of correlation from noise

Molecular dynamics simulation of liquid water and system "argon-thin water film" has been performed. In was shown that time dependence of distances between oxygen atoms of water molecules, connected by hydrogen bonds, looks like random noise and these molecules are doomed to move concertedly. The average distance between the argon atoms dissolved in water is retained for some time, so the argon atoms included in the hydrogen bond networks, but not capable to participate in hydrogen bonds are involved in concerted motions. The problem of revealing the correlations in the motion of molecules and atoms is discussed.