DOI: 10.17188/1475749
title: Materials Data on K5Na3Ta8O24 by Materials Project

description: K5Na3Ta8O24 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4/mmm 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, and faces with eight equivalent 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, and faces with eight equivalent 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, and faces with eight equivalent 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, and faces with eight equivalent 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, and faces with eight equivalent 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, and faces with eight equivalent TaO6 octahedra. There are eight shorter (2.83 Å) and four longer (2.84 Å) Na–O bond lengths. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six 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 2.00–2.02 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to one K1+, three 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 three K1+, one Na1+, and two equivalent Ta5+ atoms.