Ab initio atomic-scale determination of point-defect structure in hcp zirconium

Microstructure evolution under irradiation is very sensitive to point defects mobility. Here we present state-of-the-art ab initio calculations of the point defects structure (vacancy and self-interstitial atoms; SIAs) in hexagonal zirconium. Contrary to previous results obtained using empirical potentials, we found that the octahedral configuration should be the most stable SIA, immediately followed by the basal octahedral and the basal crowdion, the three structures having very close formation energy.