New structural insights into Fe2P2O7 – unravelling an unresolved dispute and three reversible phase transitions

Stöger, B.; Weil, M.; Glaum, R.; Fejfarova, K.; Petricek, V.; Dusek, M.; Libowitzky, E.; Füglein, E.

doi:10.1107/S2052252525007547

Figure 5
β-Fe₂P₂O₇ (thortveitite-type, C2/m, Z = 2). Crystal structure with schematic polyhedra [Fe(II)O₆] (blue) and P₂O₇⁴⁻ groups (yellow) (a) viewed along [010] and (b) as a projection onto (001); atoms given as spheres of arbitrary radius; the unit cell is indicated in red. ORTEP style representations of the polyhedra from refinement of the bridging oxygen atom O3 (c) on a single site and (d) with split sites; ellipsoids are given at the 50% probability level; symmetry codes refer to Table 4