Time and length scales for diffusion in liquids.
The first six even moments of the displacement of a molecule in water and an atom in liquid argon are found by molecular dynamics simulations and compared with the moments predicted by diffusion theory. We find a noticeable difference between the moments higher than the second. The ratio between predicted and calculated moments approaches unity as 1/t for times larger than 10 ps. Continuous time random walk is used to explain this slow approach of the moments to their diffusion limit.
Berezhkovskii
A M
AM
Center for Information Technology, National Institutes of Health, Bethesda, Maryland 20892, USA. berezh@speck.niddk.nih.gov
Sutmann
G
G
D001128:Argon / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004058:Diffusion; D008956:Models, Chemical; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
D014867:Water; D001128:Argon