Redetermination of Fe(2)[BP(3)O(12)].

Explorations of phases in the quaternary Fe(III)-B(III)-P(V)-O system prepared by the high temperature solution growth (HTSG) method led to single-crystal growth of anhydrous diiron(III) borotriphosphate, Fe(2)[BP(3)O(12)]. This phase has been synthesized previously as a microcrystalline material and its structure refined in space group P3 from powder X-ray diffraction data using the Rietveld method [Chen et al. (2004 ▶). J. Inorg. Mater.19, 429-432]. In the current single-crystal study, it was shown that the correct space group is P6(3)/m. The three-dimensional structure of the title compound is built up from FeO(6) octa-hedra (3.. symmetry), trigonal-planar BO(3) groups ( symmetry) and PO(4) tetra-hedra (m.. symmetry). Two FeO(6) octa-hedra form Fe(2)O(9) dimers via face-sharing, while the anionic BO(3) and PO(4) groups are connected via corner-sharing to build up the [BP(3)O(12)](6-) anion. Both units are inter-connected via corner-sharing.