Abstract
We present a defect chemical treatment of ceria, CeO2-δ¸ based on formation energies of point defects which we calculated using density functional theory within the GGA+U approximation. All possible defect charge states are considered. In addition we consider polarons, associates of polarons with oxygen vacancies and vacancy-vacancy repulsion. Using the above ab initio data we calculate KrögerVink diagrams and compare them to experimental data.