DOI: 10.17188/1652310
title: Materials Data on Na7TiNb2Si4P2O29F by Materials Project

description: Na7TiNb2Si4P2O25F(O2)2 is Esseneite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional and consists of four water molecules and one Na7TiNb2Si4P2O25F framework. In the Na7TiNb2Si4P2O25F framework, there are seven inequivalent Na sites. In the first Na site, Na is bonded to five O and one F atom to form NaO5F octahedra that share corners with two NaO8 hexagonal bipyramids, a cornercorner with one NbO6 octahedra, corners with two SiO4 tetrahedra, edges with two equivalent TiO5F octahedra, and edges with four NaO6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are a spread of Na–O bond distances ranging from 2.29–2.56 Å. The Na–F bond length is 2.37 Å. In the second Na site, Na is bonded to six O atoms to form NaO6 octahedra that share a cornercorner with one NbO6 octahedra, corners with four SiO4 tetrahedra, edges with two equivalent TiO5F octahedra, and edges with four NaO5F octahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Na–O bond distances ranging from 2.33–2.60 Å. In the third Na site, Na is bonded to five O and one F atom to form NaO5F octahedra that share corners with two NaO8 hexagonal bipyramids, a cornercorner with one NbO6 octahedra, corners with two SiO4 tetrahedra, edges with two equivalent TiO5F octahedra, and edges with four NaO5F octahedra. The corner-sharing octahedral tilt angles are 61°. There are a spread of Na–O bond distances ranging from 2.31–2.56 Å. The Na–F bond length is 2.28 Å. In the fourth Na site, Na is bonded to eight O atoms to form distorted NaO8 hexagonal bipyramids that share corners with two equivalent NaO8 hexagonal bipyramids, a cornercorner with one TiO5F octahedra, corners with two NaO5F octahedra, a cornercorner with one PO4 tetrahedra, and edges with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–69°. There are a spread of Na–O bond distances ranging from 2.37–2.84 Å. In the fifth Na site, Na is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Na–O bond distances ranging from 2.29–2.70 Å. In the sixth Na site, Na is bonded to seven O and one F atom to form distorted NaO7F hexagonal bipyramids that share corners with two equivalent NaO7F hexagonal bipyramids, a cornercorner with one TiO5F octahedra, corners with two NaO5F octahedra, a cornercorner with one NaO4 tetrahedra, a cornercorner with one PO4 tetrahedra, edges with two equivalent NbO6 octahedra, an edgeedge with one NaO4 tetrahedra, and edges with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–67°. There are a spread of Na–O bond distances ranging from 2.39–2.78 Å. The Na–F bond length is 2.34 Å. In the seventh Na site, Na is bonded to four O atoms to form NaO4 tetrahedra that share a cornercorner with one NaO7F hexagonal bipyramid, corners with two SiO4 tetrahedra, corners with three PO4 tetrahedra, and an edgeedge with one NaO7F hexagonal bipyramid. There are three shorter (2.29 Å) and one longer (2.43 Å) Na–O bond lengths. Ti is bonded to five O and one F atom to form TiO5F octahedra that share corners with two NaO8 hexagonal bipyramids, corners with four SiO4 tetrahedra, and edges with six NaO5F octahedra. There are a spread of Ti–O bond distances ranging from 1.72–2.07 Å. The Ti–F bond length is 2.20 Å. There are two inequivalent Nb sites. In the first Nb site, Nb is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Nb–O bond distances ranging from 1.79–2.45 Å. In the second Nb site, Nb is bonded to six O atoms to form distorted NbO6 octahedra that share corners with three NaO5F octahedra, a cornercorner with one PO4 tetrahedra, corners with four SiO4 tetrahedra, and edges with two equivalent NaO7F hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 55–61°. There are a spread of Nb–O bond distances ranging from 1.79–2.45 Å. There are four inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one TiO5F octahedra, corners with two NaO6 octahedra, a cornercorner with one SiO4 tetrahedra, and edges with two equivalent NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 58–63°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one TiO5F octahedra, corners with two NaO5F octahedra, a cornercorner with one SiO4 tetrahedra, and edges with two equivalent NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 58–66°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one TiO5F octahedra, corners with two NaO6 octahedra, corners with two equivalent NbO6 octahedra, a cornercorner with one NaO4 tetrahedra, a cornercorner with one SiO4 tetrahedra, and edges with two equivalent NaO7F hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 30–68°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one TiO5F octahedra, corners with two NaO5F octahedra, corners with two equivalent NbO6 octahedra, a cornercorner with one NaO4 tetrahedra, a cornercorner with one SiO4 tetrahedra, and edges with two equivalent NaO7F hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 34–64°. There are a spread of Si–O bond distances ranging from 1.63–1.68 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 a cornercorner with one NaO7F hexagonal bipyramid, a cornercorner with one NbO6 octahedra, and corners with two equivalent NaO4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid and a cornercorner with one NaO4 tetrahedra. There is two shorter (1.55 Å) and two longer (1.57 Å) P–O bond length. There are twenty-five inequivalent O sites. In the first O site, O is bonded in a 4-coordinate geometry to two Na, one Nb, and one Si atom. In the second O site, O is bonded in a 2-coordinate geometry to two equivalent Na and two Si atoms. In the third O site, O is bonded in a 4-coordinate geometry to two Na, one Ti, and one Si atom. In the fourth O site, O is bonded in a 2-coordinate geometry to one Na, one Nb, and one Si atom. In the fifth O site, O is bonded in a distorted rectangular see-saw-like geometry to two Na, one Ti, and one Si atom. In the sixth O site, O is bonded in a 4-coordinate geometry to two Na, one Ti, and one Si atom. In the seventh O site, O is bonded in a distorted bent 150 degrees geometry to one Na, one Nb, and one Si atom. In the eighth O site, O is bonded in a 4-coordinate geometry to three Na and one Nb atom. In the ninth O site, O is bonded in a 5-coordinate geometry to three Na and two Si atoms. In the tenth O site, O is bonded in a 2-coordinate geometry to two Na, one Nb, and one Si atom. In the eleventh O site, O is bonded in a distorted rectangular see-saw-like geometry to two Na, one Ti, and one Si atom. In the twelfth O site, O is bonded in a 2-coordinate geometry to two Na, one Nb, and one Si atom. In the thirteenth O site, O is bonded in a distorted bent 120 degrees geometry to one Na and one P atom. In the fourteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Na and one Ti atom. In the fifteenth O site, O is bonded in a 3-coordinate geometry to one Na, one Nb, and one Si atom. In the sixteenth O site, O is bonded in a 4-coordinate geometry to three Na and one Nb atom. In the seventeenth O site, O is bonded in a 1-coordinate geometry to one Na, one Nb, and one P atom. In the eighteenth O site, O is bonded in a 3-coordinate geometry to one Na, one Nb, and one Si atom. In the nineteenth O site, O is bonded in a bent 120 degrees geometry to one Na and one P atom. In the twentieth O site, O is bonded in a water-like geometry to one Na and one P atom. In the twenty-first O site, O is bonded in a distorted bent 120 degrees geometry to one Na and one P atom. In the twenty-second O site, O is bonded in a distorted single-bond geometry to one Nb and one P atom. In the twenty-third O site, O is bonded in a distorted bent 150 degrees geometry to one Na, one Nb, and one Si atom. In the twenty-fourth O site, O is bonded in a 3-coordinate geometry to two Na and one P atom. In the twenty-fifth O site, O is bonded in a bent 120 degrees geometry to one Na and one P atom. F is bonded in a rectangular see-saw-like geometry to three Na and one Ti atom.