Materials Data on K4Ba(GeO3)3 by Materials Project
K4Ba(GeO3)3 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are six inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with six GeO4 tetrahedra and faces with two equivalent BaO6 octahedra. There are a spread of K–O bond distances ranging from 2.75–2.98 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.62–3.26 Å. In the third K1+ site, K1+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.73–3.38 Å. In the fourth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.98–3.18 Å. In the fifth K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.79–3.43 Å. In the sixth K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.68–3.13 Å. Ba2+ is bonded to six O2- atoms to form distorted BaO6 octahedra that share corners with six GeO4 tetrahedra and faces with two equivalent KO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.54–2.82 Å. There are three inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent KO6 octahedra, corners with two equivalent BaO6 octahedra, and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 4–83°. There are a spread of Ge–O bond distances ranging from 1.73–1.83 Å. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent KO6 octahedra, corners with two equivalent BaO6 octahedra, and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 29–62°. There are a spread of Ge–O bond distances ranging from 1.74–1.84 Å. In the third Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent KO6 octahedra, corners with two equivalent BaO6 octahedra, and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 30–80°. There are a spread of Ge–O bond distances ranging from 1.73–1.84 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal bipyramidal geometry to three K1+ and two equivalent Ge4+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to four K1+, one Ba2+, and one Ge4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two K1+ and two Ge4+ atoms. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to three K1+ and two equivalent Ge4+ atoms. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to four K1+, one Ba2+, and one Ge4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Ge4+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to three K1+, one Ba2+, and one Ge4+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to four K1+, one Ba2+, and one Ge4+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three K1+, one Ba2+, and one Ge4+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to three K1+, one Ba2+, and one Ge4+ atom.