Tetragonal tungsten bronzes have three types of channels for ions with the smallest unusually occupied with Li in potassium lithium tantalate (KLT). This creates complexity within the crystal structure with sintering conditions affecting the final structure of KLT. For the “stoichiometric” KLT sample, there is an orthorhombic structure at room temperature. The original investigations were undertaken to confirm quantum criticality exists around 0 K. This proposal is based above room temperature, where there is a suspected ferroelastic transition, involving losing this orthorhombic distortion, into an unknown tetragonal phase. By other types of measurements attempted, structural characterisation is not possible. Neutron studies are to confirm the structure of these phases and see if they are similar to non-stoichiometric room temperature tetragonal KLT samples previously characterised.