Materials Data on Ba3Nb2(P2O9)2 by Materials Project
Ba3Nb2P4O18 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.79–3.38 Å. In the second Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.81–3.31 Å. Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with five PO4 tetrahedra. There are a spread of Nb–O bond distances ranging from 1.78–2.29 Å. 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 two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 23–45°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 34–45°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one Nb5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, one Nb5+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+, one Nb5+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Nb5+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one Nb5+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one P5+ atom.