  We use a combination of symmetry analysis and high-throughput density
functional theory calculations to search for new ferroelectric materials. We
use two search strategies to identify candidate materials. In the first
strategy, we start with non-polar materials and look for unrecognized
energy-lowering polar distortions. In the second strategy, we consider polar
materials and look for related higher symmetry structures. In both cases, if we
find new structures with the correct symmetries that are also close in energy
to experimentally known structures, then the material is likely to be
switchable in an external electric field, making it a candidate ferroelectric.
We find sixteen candidate materials, with variety of properties that are rare
in typical ferroelectrics, including large polarization, hyperferroelectricity,
antiferroelectricity, and multiferroism.
