Materials Data on Fe2Cu(P2O7)2 by Materials Project
CuFe2(P2O7)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.17 Å. Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.94 Å) and two longer (1.97 Å) Cu–O bond length. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent FeO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–50°. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent FeO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–49°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Fe3+, one Cu2+, and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to one Fe3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted linear geometry to one Fe3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Fe3+, one Cu2+, and one P5+ atom.