  Luminescence in Ce doped materials corresponds to a transition from an
excited state where the lowest Ce 5d level is filled to the ground state where
a single 4f level is filled. We have performed theoretical calculations based
on Density Functional Theory to calculate the ground state band structure of
Ce-doped materials as well as the Ce3+ excited state. The excited state
calculations used a constrained occupancy approach by setting the occupation of
the Ce 4f states to zero and allowing the first excited state above them to be
filled. These calculations were performed on a set of Ce doped materials that
are known from experiment to be scintillators or non-scintillators to relate
theoretically calculable parameters to measured scintillator performance. From
these studies we developed a set of criteria based on calculated parameters
that are necessary characteristics for bright Ce activated scintillators.
Applying these criteria to about a hundred new materials we developed a list of
candidate materials for new bright Ce activated scintillators. After synthesis
in powder form one of these new materials (Ba2YCl7:Ce) was found to be a bright
scintillator. This approach, involving first-principles calculations of modest
computing requirements was designed as a systematic, high-throughput method to
aid in the discovery of new bright scintillator materials by prioritization and
down-selection on the large number of potential new materials.
