Materials Data on Rb2Ba(Ge4O9)2 by Materials Project

Rb2Ba(Ge4O9)2 crystallizes in the trigonal P-3c1 space group. The structure is three-dimensional. Rb1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Rb–O bond distances ranging from 2.77–2.97 Å. Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.81–3.16 Å. There are seven inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to six equivalent O2- atoms to form corner-sharing GeO6 octahedra. All Ge–O bond lengths are 1.94 Å. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two GeO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–52°. There are a spread of Ge–O bond distances ranging from 1.75–1.81 Å. In the third Ge4+ site, Ge4+ is bonded to six O2- atoms to form corner-sharing GeO6 octahedra. There is three shorter (1.91 Å) and three longer (1.92 Å) Ge–O bond length. In the fourth Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two GeO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–62°. There are a spread of Ge–O bond distances ranging from 1.76–1.80 Å. In the fifth Ge4+ site, Ge4+ is bonded to six O2- atoms to form corner-sharing GeO6 octahedra. There is three shorter (1.89 Å) and three longer (1.92 Å) Ge–O bond length. In the sixth Ge4+ site, Ge4+ is bonded to six equivalent O2- atoms to form corner-sharing GeO6 octahedra. All Ge–O bond lengths are 1.94 Å. In the seventh Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two GeO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–61°. There are a spread of Ge–O bond distances ranging from 1.77–1.84 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+ and two Ge4+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ba2+ and two Ge4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and two Ge4+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Rb1+ and two Ge4+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ba2+ and two Ge4+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Rb1+ and two Ge4+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ba2+ and two Ge4+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Rb1+ and two Ge4+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Rb1+, one Ba2+, and two Ge4+ atoms.