We request one day of beam-time on POLARIS to collect Neutron Diffraction (ND) data from three novel 12H-type hexagonal perovskites that exhibit higher than expected permittivity values and a variety of dielectric anomalies related to changes in polymorphism. The purpose of the beam time is to acquire ND over a range of temperatures that will allow us to establish accurate crystallographic information related to the individual polymorphs and to unravel the relationships between them. This should allow improved understanding of the origin of the high permittivity and changes in polymorphism of these 12H-type hexagonal perovskites with future studies aimed at optimising their electrical properties.