2007/11/30 by Sungho Han, Pradeep Kumar, H. Eugene Stanley
Chemistry · Materials Science · Physics and Astronomy · #Anomaly (physics) #Chemistry #Computational chemistry #Condensed matter physics #Constant (computer programming) #Diffusion #Exponential decay #Fick's laws of diffusion #Geometry #Intermolecular force #Material Dynamics and Properties #Materials science #Molecular dynamics #Molecule #NMR spectroscopy and applications #Perpendicular #Physics #Quantum mechanics #Spectroscopy and Quantum Chemical Studies #Thermodynamics #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.77.030201
arxiv created 2007/11/30 · openalex publication_date 2008/03/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We perform molecular dynamics simulations to investigate the diffusive motion of TIP5P (the transferable intermolecular potential with five points) water in the direction perpendicular to the two hydrophobic confining walls. To calculate the diffusion constant, we use the concept of the characteristic residence time which is calculated from the exponential decay of the residence time probability density function. We find that a diffusion anomaly, increase of diffusion upon compression, is absent in the direction perpendicular to the confining walls down to the lowest temperature we simulate, 220K , whereas there is a diffusion anomaly, similar to that in bulk water, in the direction parallel to the walls. The absence of a diffusion anomaly in the direction perpendicular to the walls may arise mainly due to nanoconfinement, rather than due to the hydrophobic property of the confining walls. In addition, we find that the temperature dependence of the diffusion constant along the constant density path in the perpendicular direction shows a Vogel-Fulcher-Tammann form.