Determination of Density Functional Tight Binding Models for Cerium Allotropes

We have developed Density Functional Tight Binding models for cerium and cerium oxide with generalized gradient approximation and hybrid functionals that accurately predict the electronic band structure of different cerium polymorphs as well as the insulating oxide. We show that determination of a many-body repulsion energy with the Chebyshev Interaction Model for Simulation correctly predicts cerium allotropic energetic ordering with a minimal training created from small-scale molecular dynamics calculations of a single phase, only. Our approach determines DFTB models for both electronic and material property predictions that retain a high degree of transferability.