  We employed a recently developed semi-empirical Zr potential to determine the
diffusivities in the hcp and bcc Zr via molecular dynamics simulation. The
point defect concentration was determined directly from MD simulation rather
than from theoretical methods using T=0 calculations. We found that the
diffusion proceeds via the interstitial mechanism in the hcp Zr and both the
vacancy and interstitial mechanisms give contribution in diffusivity in the bcc
Zr. The agreement with the experimental data is excellent for the hcp Zr and
for the bcc Zr it is rather good at high temperatures but there is a
considerable disagreement at low temperatures.
