DOE OSTI2020
Na7Th2La7Ti18O54 is Orthorhombic Perovskite-derived structured and crystallizes in the orthorhombic Fmm2 space group. The structure is three-dimensional. there are seven inequivalent Na sites. In the first Na site, Na is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of Na–O bond distances ranging from 2.47–2.80 Å. In the second Na site, Na is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of Na–O bond distances ranging from 2.55–3.02 Å. In the third Na site, Na is bonded in a 12-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.53–2.74 Å. In the fourth Na site, Na is bonded in a 12-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.54–2.74 Å. In the fifth Na site, Na is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of Na–O bond distances ranging from 2.53–2.98 Å. In the sixth Na site, Na is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of Na–O bond distances ranging from 2.51–2.89 Å. In the seventh Na site, Na is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.51–2.74 Å. There are two inequivalent Th sites. In the first Th site, Th is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of Th–O bond distances ranging from 2.39–2.74 Å. In the second Th site, Th is bonded in a 12-coordinate geometry to ten O atoms. There are a spread of Th–O bond distances ranging from 2.38–2.80 Å. There are seven inequivalent La sites. In the first La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.41–3.11 Å. In the second La site, La is bonded to twelve O atoms to form distorted LaO12 cuboctahedra that share corners with four equivalent LaO12 cuboctahedra and faces with eight TiO6 octahedra. There are a spread of La–O bond distances ranging from 2.47–3.04 Å. In the third La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.47–3.10 Å. In the fourth La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.47–3.07 Å. In the fifth La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.47–3.09 Å. In the sixth La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.48–3.07 Å. In the seventh La site, La is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of La–O bond distances ranging from 2.43–3.04 Å. There are ten inequivalent Ti sites. In the first Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and faces with two equivalent LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–19°. There are a spread of Ti–O bond distances ranging from 1.86–2.15 Å. In the second Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and faces with two equivalent LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–20°. There are a spread of Ti–O bond distances ranging from 1.96–1.99 Å. In the third Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–22°. There are a spread of Ti–O bond distances ranging from 1.94–2.01 Å. In the fourth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–22°. There are a spread of Ti–O bond distances ranging from 1.94–2.01 Å. In the fifth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–22°. There are a spread of Ti–O bond distances ranging from 1.94–2.01 Å. In the sixth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–19°. There are a spread of Ti–O bond distances ranging from 1.93–2.05 Å. In the seventh Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–23°. There are a spread of Ti–O bond distances ranging from 1.84–2.13 Å. In the eighth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–30°. There are a spread of Ti–O bond distances ranging from 1.90–2.00 Å. In the ninth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–25°. There are a spread of Ti–O bond distances ranging from 1.86–2.07 Å. In the tenth Ti site, Ti is bonded to six O atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–23°. There are a spread of Ti–O bond distances ranging from 1.84–2.13 Å. There are twenty-seven inequivalent O sites. In the first O site, O is bonded to two equivalent Na, two equivalent La, and two Ti atoms to form a mixture of distorted edge and corner-sharing ONa2La2Ti2 octahedra. The corner-sharing octahedra tilt angles range from 0–9°. In the second O site, O is bonded in a 5-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the third O site, O is bonded in a 3-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the fourth O site, O is bonded in a distorted linear geometry to two equivalent La and two Ti atoms. In the fifth O site, O is bonded in a 3-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the sixth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the seventh O site, O is bonded in a distorted linear geometry to two equivalent Na, two equivalent La, and two Ti atoms. In the eighth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the ninth O site, O is bonded in a 4-coordinate geometry to two Na, two La, and two equivalent Ti atoms. In the tenth O site, O is bonded to two equivalent Na, two equivalent La, and two Ti atoms to form a mixture of distorted edge and corner-sharing ONa2La2Ti2 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the eleventh O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the twelfth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the thirteenth O site, O is bonded to two equivalent Na, two equivalent La, and two Ti atoms to form a mixture of distorted edge and corner-sharing ONa2La2Ti2 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fourteenth O site, O is bonded in a 4-coordinate geometry to two Na, two La, and two equivalent Ti atoms. In the fifteenth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the sixteenth O site, O is bonded in a distorted linear geometry to two equivalent Na, two equivalent La, and two Ti atoms. In the seventeenth O site, O is bonded in a 4-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the eighteenth O site, O is bonded in a 3-coordinate geometry to one Na, two La, and two equivalent Ti atoms. In the nineteenth O site, O is bonded in a distorted linear geometry to two equivalent La and two Ti atoms. In the twentieth O site, O is bonded in a 5-coordinate geometry to one Na, one Th, one La, and two equivalent Ti atoms. In the twenty-first O site, O is bonded in a 5-coordinate geometry to one Na, one Th, one La, and two equivalent Ti atoms. In the twenty-second O site, O is bonded in a 6-coordinate geometry to two equivalent Na, two equivalent Th, and two Ti atoms. In the twenty-third O site, O is bonded in a 4-coordinate geometry to one Na, one Th, and two equivalent Ti atoms. In the twenty-fourth O site, O is bonded in a 4-coordinate geometry to one Na, one Th, and two equivalent Ti atoms. In the twenty-fifth O site, O is bonded to two equivalent Na, two equivalent Th, and two Ti atoms to form distorted ONa2Th2Ti2 octahedra that share corners with five ONa2La2Ti2 octahedra and edges with four equivalent ONa2Th2Ti2 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the twenty-sixth O site, O is bonded in a 2-coordinate geometry to one Th, one La, and two equivalent Ti atoms. In the twenty-seventh O site, O is bonded in a 2-coordinate geometry to two Na, one Th, one La, and two equivalent Ti atoms.