The iron phosphate NaBaFe(2)(PO(4))(3).

A new iron phosphate, sodium barium diiron tris-(phosphate), NaBaFe(2)(PO(4))(3), has been synthesized by the flux method and shown to exhibit the well known langbeinite type structure. The Na, Ba and Fe atoms all lie on threefold axes, while the P and O atoms occupy general positions, one of the O atoms being disordered over two positions, with site occupancy factors of ca 0.7 and 0.3. The [Fe(2)(PO(4))(3)](∞) framework consists of FeO(6) octa-hedra sharing all their corners with the PO(4) tetra-hedra. The Na(+) and Ba(2+) cations are almost equally distributed over two distinct cavities, in which they occupy slightly different positions.