Defect Clusters in several rare-earth-doped ceria (doped with Y, Sin, Gd, Dy and Yb) containing up to four oxygen vacancies and eight dopant cations have been simulated and compared. In all doped ceria systems. the binding energy of the clusters increases with increasing cluster size and the oxygen vacancies tend to form curved chains in the clusters. Moreover, the capability of the growth of defect Cluster is affected by dopant type, which can explain the dopant type dependency of domain development with increasing doping concentration in heavily doped ceria. (C) 2009 Elsevier B.V. All rights reserved.