The recently reported double perovskite analogue imidazolium potassium iron(III) cyanide is noteworthy for two reasons. First, the order-disorder phase transitions, in which the imidazolium ion freezes into a single orientation within the host framework, are interesting in their own right, and are linked to ferroelectric transitions in the metal-formate perovskites. Second, the two very different cyanide coordination octahedra provide an ideal opportunity to isolate the effect of each on the framework flexibility. We propose a total neutron scattering study, followed by reverse Monte Carlo (RMC) analysis, to model the local correlations in this material as a function of temperature. We hope to elucidate both the behaviour of the guest (especially across the second-order phase transition, which is currently poorly understood) and the rigidity or otherwise of the surrounding framework.