DOI: 10.17188/1271218
title: Materials Data on NaNb2PO8 by Materials Project

description: NaNb2PO8 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Na–O bond distances ranging from 2.39–3.11 Å. In the second Na1+ site, Na1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Na–O bond distances ranging from 2.47–3.03 Å. There are four inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with three equivalent NbO6 octahedra and corners with three PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 7–20°. There are a spread of Nb–O bond distances ranging from 1.85–2.23 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five NbO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 5–23°. There are a spread of Nb–O bond distances ranging from 1.87–2.17 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five NbO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 7–20°. There are a spread of Nb–O bond distances ranging from 1.90–2.15 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with three equivalent NbO6 octahedra and corners with three PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 5–23°. There are a spread of Nb–O bond distances ranging from 1.84–2.24 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 four NbO6 octahedra. The corner-sharing octahedra tilt angles range from 12–34°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four NbO6 octahedra. The corner-sharing octahedra tilt angles range from 8–25°. There is three shorter (1.54 Å) and one longer (1.56 Å) P–O bond length. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Nb5+, and one P5+ atom. In the second O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Nb5+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Nb5+ atoms. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Nb5+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, one Nb5+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+, one Nb5+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+ and two Nb5+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+, one Nb5+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Nb5+ atoms. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, one Nb5+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Nb5+ atoms. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Nb5+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+, one Nb5+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a linear geometry to two equivalent Nb5+ atoms.