The structure of the UO2 (100) surface was investigated in the light of conflicting experimental data. This was facilitated by computing the surface energies of all 153 unique planar configurations that could be constructed within a repeat unit of 2×2 cubic unit cells. The relative stability of a reported partially reconstructed trench configuration was also considered. Three different interatomic potential models were employed, and for each model, a considerable number of planar configurations exhibited almost identical energies. However, the trench configuration was more stable than any planar configuration, which supports one of the experimental studies. Surface configurational energy terms were also considered.

Surface Defect Configurations on the (100) Dipolar Surface of UO2. A.H.H.Tan, M.Abramowski, R.W.Grimes, S.Owens: Physical Review B, 2005, 72[3], 035457 (6pp)