DOI: 10.17188/1475854
title: Materials Data on K5Na3Ta4Nb4O24 by Materials Project

description: 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.