DOE OSTI2020
Na11TiNb2Si4(PO13)2 is Esseneite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eleven inequivalent Na sites. In the first Na site, Na is bonded to six O atoms to form NaO6 octahedra that share corners with two NaO8 hexagonal bipyramids, corners with two NbO6 octahedra, corners with two SiO4 tetrahedra, edges with two equivalent TiO6 octahedra, and edges with four NaO6 octahedra. The corner-sharing octahedra tilt angles range from 54–61°. There are a spread of Na–O bond distances ranging from 2.33–2.64 Å. In the second Na site, Na is bonded to six O atoms to form NaO6 octahedra that share corners with two NaO8 hexagonal bipyramids, corners with two NbO6 octahedra, corners with two SiO4 tetrahedra, edges with two equivalent TiO6 octahedra, and edges with four NaO6 octahedra. The corner-sharing octahedra tilt angles range from 53–61°. There are a spread of Na–O bond distances ranging from 2.29–2.60 Å. In the third 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 TiO6 octahedra, corners with two NaO6 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 46–70°. There are a spread of Na–O bond distances ranging from 2.36–2.86 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 TiO6 octahedra, corners with two NaO6 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 43–67°. There are a spread of Na–O bond distances ranging from 2.34–2.86 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 2.28–2.68 Å. In the sixth 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 2.28–2.68 Å. In the seventh Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share corners with two NbO6 octahedra, corners with four SiO4 tetrahedra, edges with two equivalent TiO6 octahedra, and edges with four NaO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Na–O bond distances ranging from 2.36–2.62 Å. In the eighth Na site, Na is bonded in a 4-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.27–2.95 Å. In the ninth Na site, Na is bonded in a 4-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.27–2.94 Å. In the tenth Na site, Na is bonded to four O atoms to form distorted NaO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, corners with two SiO4 tetrahedra, corners with three PO4 tetrahedra, and an edgeedge with one NaO8 hexagonal bipyramid. There are a spread of Na–O bond distances ranging from 2.25–2.45 Å. In the eleventh Na site, Na is bonded to four O atoms to form distorted NaO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, corners with two SiO4 tetrahedra, corners with three PO4 tetrahedra, and an edgeedge with one NaO8 hexagonal bipyramid. There are a spread of Na–O bond distances ranging from 2.25–2.45 Å. Ti is bonded to six O atoms to form TiO6 octahedra that share corners with two NaO8 hexagonal bipyramids, corners with four SiO4 tetrahedra, and edges with six NaO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.74–2.14 Å. There are two inequivalent Nb sites. In the first Nb site, Nb is bonded to six O atoms to form distorted NbO6 octahedra that share corners with three NaO6 octahedra, a cornercorner with one PO4 tetrahedra, corners with four SiO4 tetrahedra, and edges with two equivalent NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 53–61°. There are a spread of Nb–O bond distances ranging from 1.80–2.28 Å. In the second Nb site, Nb is bonded to six O atoms to form distorted NbO6 octahedra that share corners with three NaO6 octahedra, a cornercorner with one PO4 tetrahedra, corners with four SiO4 tetrahedra, and edges with two equivalent NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 53–61°. There are a spread of Nb–O bond distances ranging from 1.80–2.28 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 TiO6 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 NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 28–68°. 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 TiO6 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 NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 28–67°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 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 NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 37–61°. 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 TiO6 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 NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 37–62°. There are a spread of Si–O bond distances ranging from 1.62–1.67 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 NaO8 hexagonal bipyramid, a cornercorner with one NbO6 octahedra, and corners with three NaO4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. There are a spread of P–O bond distances ranging from 1.55–1.59 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, a cornercorner with one NbO6 octahedra, and corners with three NaO4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of P–O bond distances ranging from 1.55–1.59 Å. There are twenty-six inequivalent O sites. In the first O site, O is bonded in a 4-coordinate geometry to two Na, one Nb, and one P atom. In the second O site, O is bonded in a 4-coordinate geometry to two Na, one Nb, and one P atom. In the third O site, O is bonded in a distorted tetrahedral geometry to three Na and one P atom. In the fourth O site, O is bonded in a distorted tetrahedral geometry to three Na and one P atom. In the fifth O site, O is bonded in a 2-coordinate geometry to two Na, one Nb, and one Si atom. In the sixth O site, O is bonded in a 2-coordinate geometry to two Na, one Nb, and one Si atom. In the seventh O site, O is bonded in a 2-coordinate geometry to three Na, one Nb, and one Si atom. In the eighth O site, O is bonded in a 1-coordinate geometry to three Na, one Nb, and one Si atom. In the ninth O site, O is bonded in a 3-coordinate geometry to one Na, one Nb, and one Si atom. In the tenth O site, O is bonded in a 3-coordinate geometry to one Na, one Nb, and one Si atom. In the eleventh O site, O is bonded in a 2-coordinate geometry to two Na, one Nb, 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 rectangular see-saw-like geometry to three 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 P atom. In the fifteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Na and one P atom. In the sixteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Na and one P atom. In the seventeenth O site, O is bonded in a rectangular see-saw-like geometry to three Na and one Ti atom. In the eighteenth O site, O is bonded to three Na and one Ti atom to form distorted corner-sharing ONa3Ti tetrahedra. In the nineteenth O site, O is bonded in a 5-coordinate geometry to three Na and two Si atoms. In the twentieth O site, O is bonded in a 5-coordinate geometry to three Na and two Si atoms. In the twenty-first O site, O is bonded in a distorted rectangular see-saw-like geometry to three Na and one Nb atom. In the twenty-second O site, O is bonded in a distorted rectangular see-saw-like geometry to three Na and one Nb atom. In the twenty-third O site, O is bonded in a 4-coordinate geometry to two Na, one Ti, and one Si atom. In the twenty-fourth O site, O is bonded in a distorted rectangular see-saw-like geometry to two Na, one Ti, and one Si atom. In the twenty-fifth O site, O is bonded to two Na, one Ti, and one Si atom to form distorted corner-sharing ONa2TiSi tetrahedra. In the twenty-sixth O site, O is bonded in a distorted rectangular see-saw-like geometry to two Na, one Ti, and one Si atom.