Origin of slow relaxation in liquid-water dynamics: A possible scenario for the presence of bottleneck in phase space

¹ Department of Physics, Tokyo Metropolitan University - Minami-Ohsawa Hachioji, Tokyo 192-0397, Japan
² Department of Computational Molecular Science, Institute for Molecular Science Myodaiji, Okazaki, Aichi, 444-8585, Japan

Received: 19 September 2005
Accepted: 26 January 2006

Abstract

We study slow relaxation in dynamics of liquid water at room temperatures and propose a consistent interpretation explaining why liquid-water dynamics exhibits power law relaxation behavior and can form the bottleneck in phase space even though it is a many-dimensional and strongly chaotic system. Our idea is inspired by recent developments of perturbation theories of Hamiltonian systems, and is reminiscent of the so-called Boltzmann-Jeans conjecture. Within this scenario, it is natural to expect that slow relaxation is not limited to liquid-water dynamics. We found that our hypothesis works well in predicting the relaxation properties of other molecules. The relation to the potential landscape picture is also discussed.