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

الملخص EN

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.