Xingfan Zhang, University College London

Polarisable shell-model potentials are widely used for modelling charged defects in solids. However, at the pure molecular mechanics (MM) level of theory, the calculated defect energetics may not satisfy the requirement of quantitative predictions and are limited to only certain charged states.

We proposed a novel strategy that employs accurate ionic polarisabilities, defect structures, and formation energies calculated by the QM/MM embedded-cluster approach in developing a shell-model potential for CeO₂. The new potential not only reproduces a wide range of physical properties of CeO₂, but also unifies the predictions of all relevant charged defects based on the Mott–Littleton approach and QM/MM electronic-structure calculations. These findings provide opportunities for accurate large-scale modelling of the partial reduction and non-stoichiometry in CeO₂, as well as a prototype for developing robust interatomic potentials for other defective crystals.