We therefore carried out DFT geometry optimisations to understand the energy scales of the disorder in this system. We created an ordered model of the structure with P1 symmetry derived from our diffraction model and geometry optimised it to confirm its stability. Next, we systematically swapped the carbon and nitrogen atoms of each the eight symmetry independent MeNH + 3 cations, one cation at a time, and geometry optimised each of the eight resultant structures. Our diffraction-derived model had the lowest energy of the nine configurations explored. The energy penalty for flipping the MeNH + 3 varied significantly, from ∆E CN = 10.4 kJmol -1 up to ∆E CN = 22.7 kJmol -1 [ESI Table 5]. The size of the energy penalty correlated with the degree of crystallographic disorder: the three well-ordered cations (MA-3, MA-5 & MA-8, numbering corresponding to the CIF file) had three highest ∆E CN , averaging ∆E CN = 19.5 kJmol -1 , whereas the five disordered cations averaged ∆E CN = 12.9 kJmol -1 . The energetic driving force for A-site vacancy/cation order was an order of magnitude larger, with the energy for displacing an MeNH + 3 cation to an adjacent cage being ∆E A2 = 102 kJmol -1 . This displacement also perturbed the octahedral tilt pattern, as one thiocyanate ligand was moved out of the cage to accommodate the MeNH + 3 cation.