Materials Data on K4BaNb5O15 by Materials Project

K4BaNb5O15 is (Cubic) Perovskite-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with two equivalent BaO12 cuboctahedra, corners with ten KO12 cuboctahedra, faces with two equivalent BaO12 cuboctahedra, faces with four KO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of K–O bond distances ranging from 2.88–2.90 Å. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with three equivalent BaO12 cuboctahedra, corners with nine KO12 cuboctahedra, a faceface with one BaO12 cuboctahedra, faces with five KO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of K–O bond distances ranging from 2.88–2.90 Å. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with two equivalent BaO12 cuboctahedra, corners with ten KO12 cuboctahedra, faces with six KO12 cuboctahedra, and faces with eight NbO6 octahedra. There are ten shorter (2.87 Å) and two longer (2.88 Å) Ba–O bond lengths. There are three inequivalent Nb+4.80+ sites. In the first Nb+4.80+ site, Nb+4.80+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra, a faceface with one BaO12 cuboctahedra, and faces with seven KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Nb–O bond distances ranging from 2.02–2.06 Å. In the second Nb+4.80+ site, Nb+4.80+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra, faces with two equivalent BaO12 cuboctahedra, and faces with six KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Nb–O bond distances ranging from 2.01–2.07 Å. In the third Nb+4.80+ site, Nb+4.80+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra, faces with two equivalent BaO12 cuboctahedra, and faces with six KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. All Nb–O bond lengths are 2.04 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Ba2+, and two Nb+4.80+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two equivalent Nb+4.80+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Ba2+, and two Nb+4.80+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Nb+4.80+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Ba2+, and two Nb+4.80+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+, two equivalent Ba2+, and two equivalent Nb+4.80+ atoms.