Hybrid HF-DFT comparative study of SrZrOs and SrTiO3(001) surface properties

Hybrid HF-DFT LCAO simulations of SrZr03 and SrTiO3(001) surface properties are performed in a single-slab model framework. The SrZrO3(001) surface was studied by an ab initio method for the first time. Three slab models with different surface terminations including up to 8 atomic planes were used for calculation of the various surface characteristics (surface energies, atomic charges, density of electronic states). The dependence of the results on the chosen model and on the kind of J-element is analyzed. The dissimilarity in the surface oxygen atom contributions to the total density of states of two crystals is attributed to the more ionic nature of Zr-0 bonds compared to Ti-0 bonds. It is found that in the case of SrZrOj the electronic density is biased towards the SrO-terminated surface and this surface should be more basic in nature than the SrO surface of SrTiO3 crystal.