The incorporation and diffusion of helium (He) with and without intrinsicvacancy defects in cubic ZrO$_{2}$ are investigated through first-principlestotal-energy calculations, in which the projector-augmented-wave (PAW) methodwith the generalized gradient approximation (GGA) is used. The calculatedformation energies of intrinsic point defects indicate that cubic ZrO$_{2}$ hasa tolerant resistance to radiation damage. The incorporation energy of Heimpurity shows that it is preferable to occupy the Zr vacancy at first, whereasthe solution energy suggests that He would be accommodated in the interstitialsite at thermodynamic equilibrium concentration. By calculating the Hemigration energies corresponding to both interstitial and vacancy assistedmechanisms, we suggest that it is most likely for He to diffuse by hoppingthrough a single vacancy. Remarkably, our calculated vacancy-assisted diffusionenergy of He is consistent well with the experimental measurement.
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