Table of Contents
Physics Research International
Volume 2011, Article ID 645264, 3 pages
Research Article

The Effect of the Anharmonicity in a Perturbation Estimate of the Self-Diffusion Coefficient

Department of Physics, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan

Received 30 September 2010; Accepted 24 January 2011

Academic Editor: Nathan Ida

Copyright © 2011 Takaki Indoh and Masaru Aniya. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A perturbative expression for the self diffusion coefficient is derived by considering that the particles are executing anharmonic vibrations around the sites with local potential minima and jump to neighbor sites after a certain waiting time. The derived expression is a natural extension of the expression obtained by Zwanzig that assumes harmonic oscillations. The relation between the low frequency oscillation and the deviation from the harmonic behavior is also shown.