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DOE OSTI2020

Materials Data on K5Na3Ta7NbO24 by Materials Project

K5Na3Ta7NbO24 is (Cubic) Perovskite-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight equivalent NaO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four equivalent KO12 cuboctahedra, a faceface with one NbO6 octahedra, and faces with seven TaO6 octahedra. There are four shorter (2.84 Å) and eight longer (2.85 Å) K–O bond lengths. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, a faceface with one NbO6 octahedra, and faces with seven TaO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight equivalent NaO12 cuboctahedra, faces with six KO12 cuboctahedra, a faceface with one NbO6 octahedra, and faces with seven TaO6 octahedra. There are four shorter (2.84 Å) and eight longer (2.85 Å) K–O bond lengths. In the fourth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight equivalent KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four equivalent NaO12 cuboctahedra, a faceface with one NbO6 octahedra, and faces with seven TaO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) K–O bond lengths. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with twelve KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four equivalent NaO12 cuboctahedra, a faceface with one NbO6 octahedra, and faces with seven TaO6 octahedra. All Na–O bond lengths are 2.83 Å. In the second Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, a faceface with one NbO6 octahedra, and faces with seven TaO6 octahedra. There are eight shorter (2.83 Å) and four longer (2.84 Å) Na–O bond lengths. There are five inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.00 Å) and three longer (2.01 Å) Ta–O bond lengths. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.00 Å) and three longer (2.01 Å) Ta–O bond lengths. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.00 Å) and three longer (2.01 Å) Ta–O bond lengths. In the fourth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.00 Å) and two longer (2.01 Å) Ta–O bond lengths. In the fifth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four equivalent TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 1.99–2.01 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.01 Å) and three longer (2.02 Å) Nb–O bond lengths. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Ta5+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the fifth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Ta5+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Ta5+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Ta5+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the ninth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Ta5+ atoms. In the tenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Ta5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Ta5+ atoms. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Ta5+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to four K1+, one Ta5+, and one Nb5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, one Ta5+, and one Nb5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K5Na3Ta6Nb2O24 by Materials Project

K5Na3Ta6Nb2O24 is (Cubic) Perovskite-derived structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are five inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight NaO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with two equivalent NbO6 octahedra, and faces with six TaO6 octahedra. There are a spread of K–O bond distances ranging from 2.84–2.86 Å. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with two equivalent NbO6 octahedra, and faces with six TaO6 octahedra. There are eight shorter (2.85 Å) and four longer (2.86 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with two equivalent NbO6 octahedra, and faces with six TaO6 octahedra. There are eight shorter (2.85 Å) and four longer (2.86 Å) K–O bond lengths. In the fourth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight NaO12 cuboctahedra, faces with six KO12 cuboctahedra, faces with two equivalent NbO6 octahedra, and faces with six TaO6 octahedra. There are four shorter (2.85 Å) and eight longer (2.86 Å) K–O bond lengths. In the fifth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four NaO12 cuboctahedra, faces with two equivalent NbO6 octahedra, and faces with six TaO6 octahedra. There are a spread of K–O bond distances ranging from 2.84–2.86 Å. There are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with twelve KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four NaO12 cuboctahedra, faces with two equivalent NbO6 octahedra, and faces with six TaO6 octahedra. There are eight shorter (2.83 Å) and four longer (2.84 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with two equivalent NbO6 octahedra, and faces with six TaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.83–2.85 Å. In the third Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with two equivalent NbO6 octahedra, and faces with six TaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.83–2.85 Å. There are three inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are five shorter (2.01 Å) and one longer (2.02 Å) Ta–O bond lengths. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Nb–O bond distances ranging from 2.01–2.03 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two equivalent Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two equivalent Ta5+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two equivalent Ta5+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two equivalent Ta5+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two equivalent Nb5+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Ta5+ atoms. In the tenth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Ta5+ atoms. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Ta5+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Ta5+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted linear geometry to four K1+, one Ta5+, and one Nb5+ atom. In the sixteenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, one Ta5+, and one Nb5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K5Na3Ta3Nb5O24 by Materials Project

K5Na3Ta3Nb5O24 is (Cubic) Perovskite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are five inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight NaO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three TaO6 octahedra, and faces with five NbO6 octahedra. There are seven shorter (2.85 Å) and five longer (2.86 Å) K–O bond lengths. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three TaO6 octahedra, and faces with five NbO6 octahedra. There are eight shorter (2.85 Å) and four longer (2.86 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three TaO6 octahedra, and faces with five NbO6 octahedra. There are eight shorter (2.85 Å) and four longer (2.86 Å) K–O bond lengths. In the fourth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight NaO12 cuboctahedra, faces with six KO12 cuboctahedra, faces with three TaO6 octahedra, and faces with five NbO6 octahedra. There are four shorter (2.85 Å) and eight longer (2.86 Å) K–O bond lengths. In the fifth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four NaO12 cuboctahedra, faces with three TaO6 octahedra, and faces with five NbO6 octahedra. There are ten shorter (2.85 Å) and two longer (2.86 Å) K–O bond lengths. There are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with twelve KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four NaO12 cuboctahedra, faces with three TaO6 octahedra, and faces with five NbO6 octahedra. All Na–O bond lengths are 2.84 Å. In the second Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three TaO6 octahedra, and faces with five NbO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) Na–O bond lengths. In the third Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three TaO6 octahedra, and faces with five NbO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) Na–O bond lengths. There are three 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 NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. There are five inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.01–2.03 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.01 Å) and three longer (2.02 Å) Nb–O bond lengths. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.01–2.03 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.01 Å) and four longer (2.02 Å) Nb–O bond lengths. In the fifth Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.01 Å) and three longer (2.02 Å) Nb–O bond lengths. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Ta5+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the seventh O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Nb5+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the tenth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Nb5+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the sixteenth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Nb5+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Ta5+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Ta5+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Nb5+ atoms. In the twentieth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Nb5+ atoms. In the twenty-first O2- site, O2- is bonded in a distorted linear geometry to four K1+, one Ta5+, and one Nb5+ atom. In the twenty-second O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, one Ta5+, and one Nb5+ atom. In the twenty-third O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Nb5+ atoms. In the twenty-fourth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Nb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K5Na3Ta2Nb6O24 by Materials Project

K5Na3Ta2Nb6O24 is (Cubic) Perovskite-derived structured and crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight equivalent NaO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four equivalent KO12 cuboctahedra, faces with two equivalent TaO6 octahedra, and faces with six NbO6 octahedra. There are four shorter (2.85 Å) and eight longer (2.86 Å) K–O bond lengths. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with two equivalent TaO6 octahedra, and faces with six NbO6 octahedra. There are eight shorter (2.85 Å) and four longer (2.86 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight equivalent NaO12 cuboctahedra, faces with six KO12 cuboctahedra, faces with two equivalent TaO6 octahedra, and faces with six NbO6 octahedra. There are four shorter (2.85 Å) and eight longer (2.86 Å) K–O bond lengths. In the fourth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight equivalent KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four equivalent NaO12 cuboctahedra, faces with two equivalent TaO6 octahedra, and faces with six NbO6 octahedra. There are eight shorter (2.85 Å) and four longer (2.86 Å) K–O bond lengths. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with twelve KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four equivalent NaO12 cuboctahedra, faces with two equivalent TaO6 octahedra, and faces with six NbO6 octahedra. All Na–O bond lengths are 2.84 Å. In the second Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with two equivalent TaO6 octahedra, and faces with six NbO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) Na–O bond lengths. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four equivalent NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 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 equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.01–2.03 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.01 Å) and three longer (2.02 Å) Nb–O bond lengths. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Nb5+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two equivalent Ta5+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two equivalent Ta5+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two equivalent Nb5+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two equivalent Nb5+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two equivalent Nb5+ atoms. In the tenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two equivalent Nb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K5Na3Ta4Nb4O24 by Materials Project

K5Na3Ta4Nb4O24 is (Cubic) Perovskite-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight equivalent NaO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four equivalent KO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four NbO6 octahedra. There are three shorter (2.84 Å) and nine longer (2.85 Å) K–O bond lengths. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four NbO6 octahedra. There are four shorter (2.84 Å) and eight longer (2.85 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight equivalent NaO12 cuboctahedra, faces with six KO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four NbO6 octahedra. There are one shorter (2.84 Å) and eleven longer (2.85 Å) K–O bond lengths. In the fourth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight equivalent KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four equivalent NaO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four NbO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) K–O bond lengths. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with twelve KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four equivalent NaO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four NbO6 octahedra. All Na–O bond lengths are 2.84 Å. In the second Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four NbO6 octahedra. There are eleven shorter (2.84 Å) and one longer (2.85 Å) Na–O bond lengths. There are three inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four equivalent NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.00 Å) and three longer (2.01 Å) Ta–O bond lengths. There are three inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.01–2.03 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four equivalent TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are one shorter (2.00 Å) and five longer (2.02 Å) Nb–O bond lengths. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are five shorter (2.01 Å) and one longer (2.02 Å) Nb–O bond lengths. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Ta5+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the seventh O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the eighth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Ta5+ atoms. In the tenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Ta5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to four K1+, one Ta5+, and one Nb5+ atom. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, one Ta5+, and one Nb5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Nb5+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Nb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K5Na3Ta5Nb3O24 by Materials Project

K5Na3Ta5Nb3O24 is (Cubic) Perovskite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are five inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight NaO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three NbO6 octahedra, and faces with five TaO6 octahedra. There are four shorter (2.84 Å) and eight longer (2.85 Å) K–O bond lengths. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three NbO6 octahedra, and faces with five TaO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three NbO6 octahedra, and faces with five TaO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) K–O bond lengths. In the fourth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight NaO12 cuboctahedra, faces with six KO12 cuboctahedra, faces with three NbO6 octahedra, and faces with five TaO6 octahedra. There are four shorter (2.84 Å) and eight longer (2.85 Å) K–O bond lengths. In the fifth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four NaO12 cuboctahedra, faces with three NbO6 octahedra, and faces with five TaO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) K–O bond lengths. There are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with twelve KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four NaO12 cuboctahedra, faces with three NbO6 octahedra, and faces with five TaO6 octahedra. All Na–O bond lengths are 2.83 Å. In the second Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three NbO6 octahedra, and faces with five TaO6 octahedra. There are eight shorter (2.83 Å) and four longer (2.84 Å) Na–O bond lengths. In the third Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with three NbO6 octahedra, and faces with five TaO6 octahedra. There are eight shorter (2.83 Å) and four longer (2.84 Å) Na–O bond lengths. There are five inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are one shorter (2.00 Å) and five longer (2.01 Å) Ta–O bond lengths. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.00 Å) and three longer (2.01 Å) Ta–O bond lengths. In the fourth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. In the fifth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. There are three inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.01 Å) and three longer (2.02 Å) Nb–O bond lengths. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four TaO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.00–2.02 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.00–2.02 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Ta5+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Ta5+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the eighth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Ta5+ atoms. In the tenth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Ta5+ atoms. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the sixteenth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the seventeenth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Ta5+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Ta5+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted linear geometry to four K1+, one Ta5+, and one Nb5+ atom. In the twentieth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, one Ta5+, and one Nb5+ atom. In the twenty-first O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Ta5+ atoms. In the twenty-second O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Ta5+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Nb5+ atoms. In the twenty-fourth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Nb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K5Na3TaNb7O24 by Materials Project

K5Na3TaNb7O24 is (Cubic) Perovskite-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight equivalent NaO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four equivalent KO12 cuboctahedra, a faceface with one TaO6 octahedra, and faces with seven NbO6 octahedra. There are four shorter (2.85 Å) and eight longer (2.87 Å) K–O bond lengths. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, a faceface with one TaO6 octahedra, and faces with seven NbO6 octahedra. There are eight shorter (2.86 Å) and four longer (2.87 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight equivalent NaO12 cuboctahedra, faces with six KO12 cuboctahedra, a faceface with one TaO6 octahedra, and faces with seven NbO6 octahedra. There are four shorter (2.86 Å) and eight longer (2.87 Å) K–O bond lengths. In the fourth K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight equivalent KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four equivalent NaO12 cuboctahedra, a faceface with one TaO6 octahedra, and faces with seven NbO6 octahedra. There are eight shorter (2.85 Å) and four longer (2.87 Å) K–O bond lengths. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with twelve KO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four equivalent NaO12 cuboctahedra, a faceface with one TaO6 octahedra, and faces with seven NbO6 octahedra. There are eight shorter (2.84 Å) and four longer (2.85 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent NaO12 cuboctahedra, corners with eight KO12 cuboctahedra, faces with two equivalent NaO12 cuboctahedra, faces with four KO12 cuboctahedra, a faceface with one TaO6 octahedra, and faces with seven NbO6 octahedra. There are a spread of Na–O bond distances ranging from 2.84–2.86 Å. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–O bond distances ranging from 2.00–2.02 Å. There are five inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four equivalent NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are five shorter (2.02 Å) and one longer (2.04 Å) Nb–O bond lengths. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.01–2.03 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.01–2.03 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.01–2.03 Å. In the fifth Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra, faces with three NaO12 cuboctahedra, and faces with five KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 2.01–2.03 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, one Ta5+, and one Nb5+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Nb5+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two K1+, two Na1+, and two Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, one Ta5+, and one Nb5+ atom. In the sixth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Nb5+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Nb5+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Na1+, and two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to four K1+, one Ta5+, and one Nb5+ atom. In the tenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, one Ta5+, and one Nb5+ atom. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Nb5+ atoms. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Nb5+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Nb5+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two Nb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K5Na3Ta2Nb6O20 by Materials Project

K5Na3Ta2Nb6O20 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twenty inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.81–3.02 Å. In the second K1+ site, K1+ is bonded in a distorted q6 geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.75–2.97 Å. In the third K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.58–3.12 Å. In the fourth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.71–3.00 Å. In the fifth K1+ site, K1+ is bonded in a 10-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.64–3.14 Å. In the sixth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.76–3.02 Å. In the seventh K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.66–3.04 Å. In the eighth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.78–3.09 Å. In the ninth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.67–2.97 Å. In the tenth K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.73–3.05 Å. In the eleventh K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.66–3.12 Å. In the twelfth K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.58–3.05 Å. In the thirteenth K1+ site, K1+ is bonded in a distorted q6 geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.76–2.96 Å. In the fourteenth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.82–2.99 Å. In the fifteenth K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.70–3.02 Å. In the sixteenth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.80–3.12 Å. In the seventeenth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.74–2.98 Å. In the eighteenth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.54–2.98 Å. In the nineteenth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.77–3.04 Å. In the twentieth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.65–3.21 Å. There are twelve 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 2.37–2.96 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 2.30–2.91 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 2.37–3.02 Å. In the fourth Na1+ site, Na1+ is bonded in a 1-coordinate geometry to nine O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–3.08 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 2.41–2.92 Å. In the sixth 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 2.40–2.96 Å. In the seventh 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 2.46–2.67 Å. In the eighth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.52–3.06 Å. In the ninth 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 2.48–2.72 Å. In the tenth 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 2.45–2.95 Å. In the eleventh Na1+ site, Na1+ is bonded in a 1-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.93 Å. In the twelfth 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 2.43–2.98 Å. There are eight inequivalent Ta4+ sites. In the first Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share a cornercorner with one NbO6 octahedra, corners with three TaO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 4–9°. There are a spread of Ta–O bond distances ranging from 1.95–2.27 Å. In the second Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share a cornercorner with one NbO6 octahedra, corners with three TaO6 octahedra, a cornercorner with one NbO4 tetrahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Ta–O bond distances ranging from 1.99–2.10 Å. In the third Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share a cornercorner with one NbO6 octahedra, corners with three TaO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–9°. There are a spread of Ta–O bond distances ranging from 1.92–2.23 Å. In the fourth Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four NbO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 2–12°. There are a spread of Ta–O bond distances ranging from 2.00–2.10 Å. In the fifth Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share a cornercorner with one NbO6 octahedra, corners with three TaO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Ta–O bond distances ranging from 1.96–2.10 Å. In the sixth Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 4–7°. There are a spread of Ta–O bond distances ranging from 1.98–2.12 Å. In the seventh Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 2–11°. There are a spread of Ta–O bond distances ranging from 1.92–2.21 Å. In the eighth Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and corners with two NbO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Ta–O bond distances ranging from 1.99–2.12 Å. There are twenty-four inequivalent Nb4+ sites. In the first Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with four NbO6 octahedra and corners with two NbO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 1–10°. There are a spread of Nb–O bond distances ranging from 2.00–2.14 Å. In the second Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with four NbO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–9°. There are a spread of Nb–O bond distances ranging from 2.04–2.22 Å. In the third Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with four NbO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 3–8°. There are a spread of Nb–O bond distances ranging from 2.03–2.12 Å. In the fourth Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share a cornercorner with one TaO6 octahedra, corners with three NbO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–4°. There are a spread of Nb–O bond distances ranging from 1.99–2.12 Å. In the fifth Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share a cornercorner with one TaO6 octahedra, corners with three NbO6 octahedra, and corners with two NbO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Nb–O bond distances ranging from 2.02–2.21 Å. In the sixth Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–9°. There are a spread of Nb–O bond distances ranging from 1.97–2.19 Å. In the seventh Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share a cornercorner with one TaO6 octahedra, corners with three NbO6 octahedra, and a cornercorner with one NbO4 tetrahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Nb–O bond distances ranging from 2.02–2.14 Å. In the eighth Nb4+ site, Nb4+ is bonded to six O2- atoms to form NbO6 octahedra that share a cornercorner with one TaO6 octahedra, corners with three NbO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–12°. There are a spread of Nb–O bond distances ranging from 2.00–2.26 Å. In the ninth Nb4+ site, Nb4+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 1.95–2.11 Å. In the tenth Nb4+ site, Nb4+ is bonded to four O2- atoms to form distorted NbO4 trigonal pyramids that share a cornercorner with one TaO6 octahedra, a cornercorner with one NbO6 octahedra, and corners with two NbO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 17–29°. There are a spread of Nb–O bond distances ranging from 1.91–2.03 Å. In the eleventh Nb4+ site, Nb4+ is bonded to four O2- atoms to form NbO4 trigonal pyramids that share a cornercorner with one TaO6 octahedra and a cornercorner with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 12–18°. There are a spread of Nb–O bond distances ranging from 1.96–2.09 Å. In the twelfth Nb4+ site, Nb4+ is bonded to four O2- atoms to form NbO4 trigonal pyramids that share a cornercorner with one TaO6 octahedra, a cornercorner with one NbO6 octahedra, a cornercorner with one NbO4 tetrahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 27–35°. There are a spread of Nb–O bond distances ranging from 1.90–2.02 Å. In the thirteenth Nb4+ site, Nb4+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 1.92–2.07 Å. In the fourteenth Nb4+ site, Nb4+ is bonded to four O2- atoms to form distorted NbO4 trigonal pyramids that share a cornercorner with one TaO6 octahedra, a cornercorner with one NbO6 octahedra, and corners wit

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K5Na3Ta3Nb5O20 by Materials Project

K5Na3Ta3Nb5O20 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twenty inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.82–3.00 Å. In the second K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.81–3.18 Å. In the third K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.58–3.03 Å. In the fourth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.82–2.97 Å. In the fifth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.64–3.15 Å. In the sixth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.73–3.00 Å. In the seventh K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.66–3.09 Å. In the eighth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.78–2.97 Å. In the ninth K1+ site, K1+ is bonded in a distorted q6 geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.69–2.95 Å. In the tenth K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.73–3.03 Å. In the eleventh K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.66–3.12 Å. In the twelfth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.74–2.94 Å. In the thirteenth K1+ site, K1+ is bonded in a distorted q6 geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.78–2.93 Å. In the fourteenth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.81–2.93 Å. In the fifteenth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.72–2.99 Å. In the sixteenth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.78–3.00 Å. In the seventeenth K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.76–3.13 Å. In the eighteenth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.53–2.99 Å. In the nineteenth K1+ site, K1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.79–3.03 Å. In the twentieth K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.65–3.27 Å. There are twelve 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 2.38–2.94 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 2.31–2.86 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 2.37–3.03 Å. In the fourth Na1+ site, Na1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Na–O bond distances ranging from 2.65–3.09 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 2.40–2.91 Å. In the sixth 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 2.38–2.96 Å. In the seventh 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 2.45–2.68 Å. In the eighth 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 2.48–2.88 Å. In the ninth 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 2.48–2.73 Å. In the tenth 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 2.42–2.92 Å. In the eleventh Na1+ site, Na1+ is bonded in a 1-coordinate geometry to nine O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–3.07 Å. In the twelfth 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 2.45–2.98 Å. There are twelve inequivalent Ta+4.33+ sites. In the first Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 3–10°. There are a spread of Ta–O bond distances ranging from 1.93–2.27 Å. In the second Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Ta–O bond distances ranging from 1.95–2.12 Å. In the third Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–10°. There are a spread of Ta–O bond distances ranging from 1.92–2.27 Å. In the fourth Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two TaO6 octahedra, corners with two NbO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–14°. There are a spread of Ta–O bond distances ranging from 1.96–2.16 Å. In the fifth Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–5°. There are a spread of Ta–O bond distances ranging from 1.95–2.12 Å. In the sixth Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two TaO6 octahedra, corners with two NbO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 3–10°. There are a spread of Ta–O bond distances ranging from 1.99–2.07 Å. In the seventh Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Ta–O bond distances ranging from 1.94–2.16 Å. In the eighth Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Ta–O bond distances ranging from 1.94–2.16 Å. In the ninth Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two TaO6 octahedra, corners with two NbO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–13°. There are a spread of Ta–O bond distances ranging from 1.95–2.19 Å. In the tenth Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–10°. There are a spread of Ta–O bond distances ranging from 1.93–2.16 Å. In the eleventh Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two TaO6 octahedra, corners with two NbO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Ta–O bond distances ranging from 1.97–2.10 Å. In the twelfth Ta+4.33+ site, Ta+4.33+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and corners with two NbO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 1–9°. There are a spread of Ta–O bond distances ranging from 1.97–2.13 Å. There are twenty inequivalent Nb+3.80+ sites. In the first Nb+3.80+ site, Nb+3.80+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two TaO6 octahedra, corners with two NbO6 octahedra, and corners with two NbO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 1–13°. There are a spread of Nb–O bond distances ranging from 2.00–2.16 Å. In the second Nb+3.80+ site, Nb+3.80+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two TaO6 octahedra, corners with two NbO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Nb–O bond distances ranging from 2.03–2.20 Å. In the third Nb+3.80+ site, Nb+3.80+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two TaO6 octahedra, corners with two NbO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–5°. There are a spread of Nb–O bond distances ranging from 2.00–2.12 Å. In the fourth Nb+3.80+ site, Nb+3.80+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two TaO6 octahedra, corners with two NbO6 octahedra, and a cornercorner with one NbO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 1–14°. There are a spread of Nb–O bond distances ranging from 2.00–2.26 Å. In the fifth Nb+3.80+ site, Nb+3.80+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 1.94–2.13 Å. In the sixth Nb+3.80+ site, Nb+3.80+ is bonded to four O2- atoms to form distorted NbO4 trigonal pyramids that share a cornercorner with one TaO6 octahedra, a cornercorner with one NbO6 octahedra, and corners with two NbO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 20–30°. There are a spread of Nb–O bond distances ranging from 1.91–2.02 Å. In the seventh Nb+3.80+ site, Nb+3.80+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 1.97–2.09 Å. In the eighth Nb+3.80+ site, Nb+3.80+ is bonded to four O2- atoms to form NbO4 trigonal pyramids that share a cornercorner with one TaO6 octahedra, a cornercorner with one NbO6 octahedra, and corners with two NbO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 27–34°. There are a spread of Nb–O bond distances ranging from 1.91–2.02 Å. In the ninth Nb+3.80+ site, Nb+3.80+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 1.93–2.09 Å. In the tenth Nb+3.80+ site, Nb+3.80+ is bonded to four O2- atoms to form distorted NbO4 trigonal pyramids that share corners with two TaO6 octahedra and corners with two NbO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 20–35°. There are a spread of Nb–O bond distances ranging from 1.91–2.01 Å. In the eleventh Nb+3.80+ site, Nb+3

36 MATERIALS SCIENCE↗