DOE OSTI2020
Ca10Ti4Ta3Al3(SiO5)10 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are five 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 2.28–2.78 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 2.29–2.78 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 2.28–2.79 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 2.28–2.64 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 2.27–2.65 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–38°. There are a spread of Ti–O bond distances ranging from 1.87–2.05 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–38°. There are a spread of Ti–O bond distances ranging from 1.87–2.06 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent AlO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–38°. There are a spread of Ta–O bond distances ranging from 1.92–2.06 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent AlO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Ta–O bond distances ranging from 1.92–2.05 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent TaO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–38°. There are a spread of Al–O bond distances ranging from 1.84–2.02 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent TaO6 octahedra and corners with four equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Al–O bond distances ranging from 1.84–2.01 Å. There are five 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 TiO6 octahedra, a cornercorner with one TaO6 octahedra, and corners with two equivalent AlO6 octahedra. The corner-sharing octahedra tilt angles range from 37–51°. There are a spread of Si–O bond distances ranging from 1.64–1.68 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two TaO6 octahedra and corners with two equivalent AlO6 octahedra. The corner-sharing octahedra tilt angles range from 37–53°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two TaO6 octahedra and corners with two equivalent AlO6 octahedra. The corner-sharing octahedra tilt angles range from 36–53°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TaO6 octahedra and corners with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 37–54°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. 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 three shorter (1.65 Å) and one longer (1.66 Å) Si–O bond length. There are twenty-five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ta5+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ta5+, and one Al3+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ta5+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+, one Ta5+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ta5+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ta5+, and one Al3+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Al3+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ta5+, and one Al3+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ta5+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Ta5+, and one Si4+ atom. 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 4-coordinate geometry to two Ca2+, one Ti4+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Ti4+ atoms. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, 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 4-coordinate geometry to two Ca2+, 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 4-coordinate geometry to two equivalent Ca2+, one Ti4+, and one Si4+ atom. In the twenty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the twenty-fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ti4+ atoms.