“…More recently, the realization of transition metal-pnictogen frameworks, also known as “unconventional clathrates”, has further increased the number of elements included in clathrate frameworks . So far, this clathrate subgroup contains transition metals Ni, Pd, Cu, Zn, Cd, Au, and pnictogens P, As, and Sb. − Transition metal-pnictogen clathrates have been shown to exhibit superstructural orderings in many cases , or the formation of new clathrate types or “clathrate-like” structures. ,,, The divergence from the archetypal symmetry Pm 3̅ n has been explained empirically by noting that metal–metal bonds in the framework are avoided in supercells. This leads to an ordering preference of elements among the crystallographic sites, creating the need for a larger and less symmetric unit cell to describe the crystal structure.…”