. The primary mechanism by which the charge of aliovalent M(II) cations is accommodated by the frameworks is through the introduction of Bi(SCN) 6 vacancies, analogous to the M(CN) 6 vacancies found in the Prussian Blue; however anti-site defects, large water clusters and even neutral molecular metal complexes are also accommodated. In addition to this, we find that the low symmetry of the structure enables long-range order of these defects: we find that vacancies tend to segregate into {100} or {110} type layers. The complexity of these structures is such that single-crystal X-ray diffraction data is necessary to uncover it. Despite the relatively high concentration of vacancies, we also found that the octahedral tilt patterns of the pattern structures are retained in all the Prussian Blue-derived members of this family, showing their robust nature. Compounds 3 and 4 demonstrate that as in the Prussian Blues, the presence of other cations can have a powerful effect on the resultant structure, as their incorporation leads to drastically different ordering patterns.