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

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=D₀ i/rexp(-Eₐ/kBT) with Eₐ=0.099 eV, D₀=0.84×{}10^-3 cm²/sec, compared to the most recent experimental values of Eₐ=0.096 eV, D₀=0.86×{}10^-3 cm²/sec.