2009 Volume 7 Pages 413-420
Interatomic potentials (IP) have demonstrated considerable application in the study of bulk and surfaces of ceria (CeO2), and also the long range component in QM/MM calculations. Despite the development and ability of several IPs to reproduce the structural and dielectric properties of bulk ceria, in the absence of high quality electronic structure calculations it remains unclear how well these models perform when applied to surfaces. In this paper we present a comparison of several IPs from the literature in comparison with periodic density functional theory (GGA+U) for the calculation of the (111), (110) and (100) low index surfaces of ceria. While the IP approach reproduces the correct order of surface stability ((111)> (110) > (100)) and relaxation ((100)> (110) > (111)) found in the application of GGA+U, the surface energies calculated with IPs are considerably larger than those found with GGA+U. Based on the most comparable IP tested against GGA+U, we have performed trial QM/MM embedded-cluster calculations on the stoichiometric and defect (110) surface of ceria and compared the resulting defect energy with GGA+U. [DOI: 10.1380/ejssnt.2009.413]
