First-principles calculation of the activation energy for diffusion in liquid sodium

Abstract

We have performed the first calculation of the activation energy for self-diffusion in a liquid metal which contains no adjustable parameters. The calculation uses the local-density-functional theory combined with the Car-Parrinello technique for molecular-dynamics simulation. The coefficient of self-diffusion agrees well with the experimental value and fits the form D=${\mathit{D}}_0$ i/rexp(-${\mathit{E}}_{\mathit{a}}$/${\mathit{k}}_{\mathit{B}}$T) with ${\mathit{E}}_{\mathit{a}}$=0.099 eV, ${\mathit{D}}_0$=0.84×${10}^{\mathrm{-}3}$ ${\mathrm{cm}}^2$/sec, compared to the most recent experimental values of ${\mathit{E}}_{\mathit{a}}$=0.096 eV, ${\mathit{D}}_0$=0.86×${10}^{\mathrm{-}3}$ ${\mathrm{cm}}^2$/sec.