Materials Data on BiP2O7 by Materials Project
BiP2O7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. Bi5+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Bi–O bond distances ranging from 2.26–2.30 Å. There are two inequivalent P+4.50+ sites. In the first P+4.50+ site, P+4.50+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent BiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–50°. There are a spread of P–O bond distances ranging from 1.53–1.62 Å. In the second P+4.50+ site, P+4.50+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent BiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–52°. There is three shorter (1.54 Å) and one longer (1.61 Å) P–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Bi5+ and one P+4.50+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Bi5+ and one P+4.50+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Bi5+ and one P+4.50+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Bi5+ and one P+4.50+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Bi5+ and one P+4.50+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Bi5+ and one P+4.50+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P+4.50+ atoms.