We find that for this family of compounds the A-site order and tilts are strongly coupled: each tilt sequence has its own cation order. Columnar order in 1 and 2 accompanies the a -a -c + tilt , the unique A-site order in 3 is accompanied by the unique complex a + b ++-++-c +-+-tilt, and the Cu 3 Au order occurs with a + a + a + tilt. One possible reason for this can be seen in the distribution of NCS -anions between pseudocubic cages [Fig. ]. Each NCS - must lie within one of four adjacent pseudocubic cages, with which cage it lies within determined by the tilting of two metal octahedra it is connected to [Fig. ]. Each cage is bounded by 12 thiocyanates, so on average a cage contains three thiocyanates. In 4 one quarter of the cages contain no NCS -, with 4 containing four thiocyanates [Fig. . We find that the pseudocubic cages containing no NCS -are the cages containing Gua + cations, whereas the pseudocubic cages containing four NCS -contain no A-site cations. This correlation likely arise from simple reasons of sterics: there is not enough space in the cages containing four thiocyanates for an A-site cation. This approach is in agreement with previous rationalisations of the structures of CaCu 3 Ti 4 O 12type perovskites, which also have a + a + a + tiles and Cu 3 Au A-site order, where the largest cation (e.g. Ca 2+ ) sits in the cages containing no O 2 -anions. The pseudocubic cages in 3 contain 0, 2, 3 and 4 NCS -anions in the ratio 1:3:2:6; each and every pseudocubic cage which does not contain an A-site cation contains four NCS -anions [Fig. ]. This suggests that the complex tilt pattern derives, in part, from the need to rearrange the NCS -anions to accommodate the larger MeNH + 3 cations in the pseudocubic cages. This ability of octahedral tilts to increase the available volume in some cages, at the expense of others, provides an explanation for why the average, rather than maximum, A-site cation size appears to be the key factor for perovskite stability. In contrast, all the cages in 1 and 2 contain three NCS -and so cooperative framework shear therefore is necessary to accommodate the A-site cations. We have applied this anion-in-cage counting method to each of the four simplest 3-tilt patterns (in the approximation that all tilts have equal magnitude) [Tbl. 4]. We find that these tilts, aside from the previously mentioned a + a + a + tilt sequence, would not be expected to stabilise any particular A-site cation order according to this counting method, as all cages contain three NCS -, even if the cages are symmetry distinct. This suggests that complex tilts may be well be favoured in molecular perovskites with large A-site cation size disparities.