Materials Data on Na3(PO4)2 by Materials Project
Na3(PO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Na sites. In the first Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share a cornercorner with one NaO6 octahedra, corners with five PO4 tetrahedra, and edges with four NaO6 octahedra. The corner-sharing octahedral tilt angles are 45°. There are a spread of Na–O bond distances ranging from 2.36–2.68 Å. In the second Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with three PO4 tetrahedra, edges with five NaO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–71°. There are a spread of Na–O bond distances ranging from 2.35–2.75 Å. In the third Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share corners with three NaO6 octahedra, corners with five PO4 tetrahedra, and edges with three NaO6 octahedra. The corner-sharing octahedra tilt angles range from 45–71°. There are a spread of Na–O bond distances ranging from 2.34–2.65 Å. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with six NaO6 octahedra, a cornercorner with one PO4 tetrahedra, and an edgeedge with one NaO6 octahedra. The corner-sharing octahedra tilt angles range from 42–60°. There are a spread of P–O bond distances ranging from 1.52–1.65 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with seven NaO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 38–63°. There are a spread of P–O bond distances ranging from 1.52–1.64 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to two Na and one P atom. In the second O site, O is bonded in a 3-coordinate geometry to two Na and one P atom. In the third O site, O is bonded in a rectangular see-saw-like geometry to three Na and one P atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to two P atoms. In the fifth O site, O is bonded in a distorted T-shaped geometry to three Na atoms. In the sixth O site, O is bonded to three Na and one P atom to form distorted corner-sharing ONa3P tetrahedra. In the seventh O site, O is bonded in a 3-coordinate geometry to two Na and one P atom. In the eighth O site, O is bonded in a 4-coordinate geometry to three Na and one P atom.