Near Surface Stoichiometry in UO₂: A Density Functional Theory Study

Figure 1

The slab structure of (a) pristine in the direction perpendicular to the (110) surface, in which each layer is the stoichiometric UO₂; (b) O vacancy on the defective (110) plane corresponding to UO_1.833; and (c) O interstitial on the defective (110) plane corresponding to UO_2.167. O atoms are shown in red color, U atoms in grey, and defects in green. The bottommost fixed bilayer is marked as layer of 0 and 1.

(a)

(b)

(c)