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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on NaMn(SiO3)2 by Materials Project

NaMnSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.36–2.86 Å. Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with two equivalent MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.94–2.23 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent MnO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–60°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Mn3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Mn3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na13Mn5(SiO3)12 by Materials Project

Na13Mn5(SiO3)12 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are nine inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to eight O2- atoms to form distorted NaO8 hexagonal bipyramids that share corners with three NaO8 hexagonal bipyramids, a cornercorner with one SiO4 tetrahedra, an edgeedge with one NaO8 hexagonal bipyramid, edges with two MnO6 octahedra, edges with five SiO4 tetrahedra, and a faceface with one MnO6 octahedra. There are a spread of Na–O bond distances ranging from 2.34–2.74 Å. In the second Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.29–2.91 Å. In the third Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.91 Å. In the fourth Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.37–3.02 Å. In the fifth Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.54–2.82 Å. In the sixth 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 2.63–2.94 Å. In the seventh Na1+ site, Na1+ is bonded to eight O2- atoms to form distorted NaO8 hexagonal bipyramids that share corners with two equivalent NaO8 hexagonal bipyramids, corners with two SiO4 tetrahedra, edges with two equivalent MnO6 octahedra, edges with four SiO4 tetrahedra, a faceface with one NaO6 octahedra, and a faceface with one MnO6 octahedra. There are a spread of Na–O bond distances ranging from 2.22–2.75 Å. In the eighth Na1+ site, Na1+ is bonded to eight O2- atoms to form distorted NaO8 hexagonal bipyramids that share corners with two SiO4 tetrahedra, edges with two equivalent NaO8 hexagonal bipyramids, edges with two equivalent MnO6 octahedra, edges with four SiO4 tetrahedra, and faces with two MnO6 octahedra. There are a spread of Na–O bond distances ranging from 2.22–2.81 Å. In the ninth Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with six SiO4 tetrahedra, a faceface with one NaO8 hexagonal bipyramid, and a faceface with one MnO6 octahedra. There are a spread of Na–O bond distances ranging from 2.30–2.60 Å. There are five inequivalent Mn+2.20+ sites. In the first Mn+2.20+ site, Mn+2.20+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SiO4 tetrahedra, edges with four NaO8 hexagonal bipyramids, a faceface with one NaO6 octahedra, and a faceface with one MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.96–2.15 Å. In the second Mn+2.20+ site, Mn+2.20+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SiO4 tetrahedra, edges with two equivalent NaO8 hexagonal bipyramids, and faces with two MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.17–2.24 Å. In the third Mn+2.20+ site, Mn+2.20+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six SiO4 tetrahedra, edges with two equivalent NaO8 hexagonal bipyramids, a faceface with one NaO8 hexagonal bipyramid, and a faceface with one MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.17–2.47 Å. In the fourth Mn+2.20+ site, Mn+2.20+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six SiO4 tetrahedra, faces with three NaO8 hexagonal bipyramids, and a faceface with one MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.14–2.61 Å. In the fifth Mn+2.20+ site, Mn+2.20+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SiO4 tetrahedra, a faceface with one NaO8 hexagonal bipyramid, and a faceface with one MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.22–2.44 Å. There are eight inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, corners with three MnO6 octahedra, corners with two equivalent SiO4 tetrahedra, and edges with two equivalent NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–46°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, corners with three MnO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–51°. There is two shorter (1.62 Å) and two longer (1.67 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, corners with three MnO6 octahedra, corners with two equivalent SiO4 tetrahedra, and edges with two equivalent NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 31–46°. There is two shorter (1.61 Å) and two longer (1.66 Å) Si–O bond length. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, a cornercorner with one MnO6 octahedra, corners with two equivalent NaO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 29–52°. There are a spread of Si–O bond distances ranging from 1.59–1.66 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MnO6 octahedra, corners with two SiO4 tetrahedra, and edges with two NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 34–47°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MnO6 octahedra, corners with two SiO4 tetrahedra, and edges with two NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 33–44°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, a cornercorner with one NaO6 octahedra, corners with two MnO6 octahedra, corners with two SiO4 tetrahedra, and an edgeedge with one NaO8 hexagonal bipyramid. The corner-sharing octahedra tilt angles range from 29–54°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two MnO6 octahedra, corners with two SiO4 tetrahedra, and edges with two NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 36–46°. There are a spread of Si–O bond distances ranging from 1.60–1.68 Å. There are twenty-two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Na1+, one Mn+2.20+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three Na1+, one Mn+2.20+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+, one Mn+2.20+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mn+2.20+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to five Na1+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, one Mn+2.20+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and two Si4+ atoms. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a 5-coordinate geometry to two Na1+, two Mn+2.20+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 5-coordinate geometry to two Na1+, two Mn+2.20+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Mn+2.20+, and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Mn+2.20+, and one Si4+ atom. In the seventeenth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mn+2.20+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mn+2.20+, and one Si4+ atom. In the nineteenth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Mn+2.20+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Si4+ atom. In the twenty-first O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+, one Mn+2.20+, and one Si4+ atom. In the twenty-second O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, two Mn+2.20+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2Mn2Si2O7 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaMn2(SiO3)3 by Materials Project

NaMn2(SiO3)3 is Esseneite-like structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.27–2.77 Å. There are two inequivalent Mn+2.50+ sites. In the first Mn+2.50+ site, Mn+2.50+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six SiO4 tetrahedra and an edgeedge with one MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.93–2.42 Å. In the second Mn+2.50+ site, Mn+2.50+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mn–O bond distances ranging from 1.97–2.60 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent MnO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 28–59°. There are a spread of Si–O bond distances ranging from 1.60–1.68 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MnO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent MnO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–62°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mn+2.50+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Mn+2.50+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Mn+2.50+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Mn+2.50+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Mn+2.50+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Mn+2.50+ and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2Mn(SiO3)2 by Materials Project

Na2Mn(SiO3)2 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.84 Å. In the second Na1+ site, Na1+ is bonded to eight O2- atoms to form distorted NaO8 hexagonal bipyramids that share corners with three NaO8 hexagonal bipyramids, a cornercorner with one SiO4 tetrahedra, an edgeedge with one NaO8 hexagonal bipyramid, edges with two MnO6 octahedra, edges with five SiO4 tetrahedra, and a faceface with one MnO6 octahedra. There are a spread of Na–O bond distances ranging from 2.32–2.81 Å. In the third Na1+ site, Na1+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.56–2.74 Å. In the fourth Na1+ site, Na1+ is bonded to eight O2- atoms to form distorted NaO8 hexagonal bipyramids that share corners with two equivalent NaO8 hexagonal bipyramids, corners with two SiO4 tetrahedra, edges with two equivalent NaO8 hexagonal bipyramids, edges with two equivalent MnO6 octahedra, edges with four SiO4 tetrahedra, and faces with two MnO6 octahedra. There are a spread of Na–O bond distances ranging from 2.20–2.79 Å. There are three inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SiO4 tetrahedra, edges with four NaO8 hexagonal bipyramids, and faces with two MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.18–2.23 Å. In the second Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SiO4 tetrahedra, faces with three NaO8 hexagonal bipyramids, and a faceface with one MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.21–2.42 Å. In the third Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SiO4 tetrahedra, edges with two equivalent NaO8 hexagonal bipyramids, a faceface with one NaO8 hexagonal bipyramid, and a faceface with one MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.19–2.44 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, corners with three MnO6 octahedra, corners with two equivalent SiO4 tetrahedra, and edges with two equivalent NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 34–53°. There is two shorter (1.62 Å) and two longer (1.66 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MnO6 octahedra, corners with two SiO4 tetrahedra, and edges with three NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 34–44°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, corners with three MnO6 octahedra, corners with two SiO4 tetrahedra, and edges with two NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 33–44°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO8 hexagonal bipyramid, corners with three MnO6 octahedra, corners with two equivalent SiO4 tetrahedra, and edges with two equivalent NaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 34–51°. There is two shorter (1.62 Å) and two longer (1.66 Å) Si–O bond length. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mn2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Mn2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mn2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, two Mn2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to two Na1+, two Mn2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to three Na1+, one Mn2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Mn2+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to three Na1+, one Mn2+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na5Mn4(SiO3)6 by Materials Project

Na5Mn4(SiO3)6 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.56–2.73 Å. In the second Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.89 Å. In the third Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.86 Å. There are four inequivalent Mn+3.75+ sites. In the first Mn+3.75+ site, Mn+3.75+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SiO4 tetrahedra and a faceface with one MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.21–2.40 Å. In the second Mn+3.75+ site, Mn+3.75+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SiO4 tetrahedra and faces with two MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.19–2.21 Å. In the third Mn+3.75+ site, Mn+3.75+ is bonded in a 2-coordinate geometry to four O2- atoms. There are a spread of Mn–O bond distances ranging from 2.09–2.53 Å. In the fourth Mn+3.75+ site, Mn+3.75+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six SiO4 tetrahedra and a faceface with one MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.17–2.46 Å. There are four inequivalent Si+2.67+ sites. In the first Si+2.67+ site, Si+2.67+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MnO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–53°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the second Si+2.67+ site, Si+2.67+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MnO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–44°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the third Si+2.67+ site, Si+2.67+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MnO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 35–44°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the fourth Si+2.67+ site, Si+2.67+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MnO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–55°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Mn+3.75+, and one Si+2.67+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mn+3.75+, and one Si+2.67+ atom. In the third O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mn+3.75+, and one Si+2.67+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two Na1+ and two Si+2.67+ atoms. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Mn+3.75+, and one Si+2.67+ atom. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mn+3.75+, and one Si+2.67+ atom. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to one Na1+, three Mn+3.75+, and one Si+2.67+ atom. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two Mn+3.75+, and one Si+2.67+ atom. In the ninth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+, two Mn+3.75+, and one Si+2.67+ atom. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and two Si+2.67+ atoms. In the eleventh O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and two Si+2.67+ atoms.

36 MATERIALS SCIENCE↗