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DOE OSTI2020

Materials Data on NaCa9Ti9Nb(SiO5)10 by Materials Project

NaCa9Ti9Nb(SiO5)10 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.29–2.84 Å. There are nine inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.61 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.63 Å. In the third Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.63 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.63 Å. In the fifth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.26–2.73 Å. In the sixth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.65 Å. In the seventh Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.27–2.64 Å. In the eighth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.63 Å. In the ninth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.63 Å. There are nine inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one TiO6 octahedra, a cornercorner with one NbO6 octahedra, and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–39°. There are a spread of Ti–O bond distances ranging from 1.89–2.08 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one TiO6 octahedra, a cornercorner with one NbO6 octahedra, and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–39°. There are a spread of Ti–O bond distances ranging from 1.83–2.08 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Ti–O bond distances ranging from 1.84–2.05 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–39°. There are a spread of Ti–O bond distances ranging from 1.84–2.05 Å. In the fifth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Ti–O bond distances ranging from 1.85–2.04 Å. In the sixth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Ti–O bond distances ranging from 1.85–2.04 Å. In the seventh Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Ti–O bond distances ranging from 1.85–2.05 Å. In the eighth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Ti–O bond distances ranging from 1.85–2.04 Å. In the ninth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Ti–O bond distances ranging from 1.87–2.05 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–39°. There are a spread of Nb–O bond distances ranging from 1.88–2.08 Å. There are ten 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 NbO6 octahedra and corners with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 35–54°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NbO6 octahedra and corners with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 37–53°. There is three shorter (1.65 Å) and one longer (1.66 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 NbO6 octahedra and corners with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 37–53°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 36–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NbO6 octahedra and corners with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 34–51°. There is three shorter (1.65 Å) and one longer (1.66 Å) Si–O bond length. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 36–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 36–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 36–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the ninth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 36–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the tenth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 36–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. There are fifty inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ti4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Nb5+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Ti4+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one Nb5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Nb5+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Nb5+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ti4+ atoms. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the seventeenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Ti4+, and one Nb5+ atom. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the nineteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Ti4+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the twenty-first O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Nb5+, and one Si4+ atom. In the twenty-second O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the twenty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ti4+ atoms. In the twenty-fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the twenty-sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Ti4+ atoms. In the twenty-eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the twenty-ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the thirtieth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the thirty-first O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the thirty-second O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the thirty-third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the thirty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ti4+ atoms. In the thirty-fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the thirty-sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ti4+ atoms. In the thirty-seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the thirty-eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the thirty-ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the fortieth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the forty-first O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on NaCa4Ti4Nb(SiO5)5 by Materials Project

NaCa4Ti4Nb(SiO5)5 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.30–2.85 Å. In the second Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.30–2.82 Å. There are eight inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.29–2.67 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.29–2.70 Å. In the third Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.27–2.70 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.29–2.67 Å. In the fifth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.75 Å. In the sixth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.29–2.72 Å. In the seventh Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.29–2.68 Å. In the eighth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.29–2.66 Å. There are eight inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of Ti–O bond distances ranging from 1.85–2.04 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one TiO6 octahedra, a cornercorner with one NbO6 octahedra, and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 38–39°. There are a spread of Ti–O bond distances ranging from 1.86–2.03 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two NbO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–40°. There are a spread of Ti–O bond distances ranging from 1.84–2.03 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one TiO6 octahedra, a cornercorner with one NbO6 octahedra, and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 39°. There are a spread of Ti–O bond distances ranging from 1.84–2.03 Å. In the fifth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 38–39°. There are a spread of Ti–O bond distances ranging from 1.89–2.05 Å. In the sixth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of Ti–O bond distances ranging from 1.87–2.03 Å. In the seventh Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of Ti–O bond distances ranging from 1.86–2.04 Å. In the eighth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of Ti–O bond distances ranging from 1.86–2.03 Å. There are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 39°. There are a spread of Nb–O bond distances ranging from 1.88–2.08 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–40°. There are a spread of Nb–O bond distances ranging from 1.86–2.07 Å. There are ten inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent TiO6 octahedra and corners with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 37–53°. There is three shorter (1.65 Å) and one 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 two equivalent TiO6 octahedra and corners with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 36–54°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 38–53°. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 38–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 38–53°. There is one shorter (1.65 Å) and three longer (1.66 Å) Si–O bond length. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent TiO6 octahedra and corners with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 36–51°. 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 corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 37–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent TiO6 octahedra and corners with two equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 36–51°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the ninth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 38–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the tenth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 37–53°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. There are fifty inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Nb5+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Ti4+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Nb5+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Ti4+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Nb5+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Ti4+, and one Nb5+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Nb5+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Ti4+, and one Nb5+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Ti4+, and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Ti4+, and one Nb5+ atom. In the nineteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Nb5+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the twenty-first O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Ti4+, and one Si4+ atom. In the twenty-second O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the twenty-third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Ti4+, and one Nb5+ atom. In the twenty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Nb5+, and one Si4+ atom. In the twenty-fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the twenty-sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Ti4+, and one Si4+ atom. In the twenty-seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the twenty-eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Ti4+ atoms. In the twenty-ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Nb5+, and one Si4+ atom. In the thirtieth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the thirty-first O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Ti4+, and one Si4+ atom. In the thirty-second O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the thirty-third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Ti4+ atoms. In the thirty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Nb5+, and one Si4+ atom. In the thirty-fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the thirty-sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Ti4+, and one Si4+ atom. In the thirty-seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ti4+ atoms. In the thirty-eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the thirty-ni

36 MATERIALS SCIENCE↗