Self-diffusion constants in silicon: Ab initio calculations in combination with classical rate theory

Abstract

We demonstrate that local-density approximation in combination with the dynamical matrix method is a plausible method for calculating diffusion constants in solids. Especially we compute the diffusivity of the neutral self-interstitial in silicon bulk. The climbing image nudged elastic band method is used for the energy barrier and the transition state atomic configuration. The diffusion prefactor is obtained by using a classical rate theory, the dynamical matrix method. We compare with the diffusivity from another alternative way, ab initio molecular-dynamics simulations, at 1500 K. They are in good agreement.