Materials Data on Rb2Ge4O9 by Materials Project
Rb2Ge4O9 crystallizes in the trigonal P-3c1 space group. The structure is three-dimensional. Rb1+ is bonded in a 7-coordinate geometry to nine O2- atoms. There are a spread of Rb–O bond distances ranging from 2.87–3.44 Å. There are four 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 GeO6 octahedra and corners with two equivalent GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There is two shorter (1.76 Å) and two longer (1.82 Å) Ge–O bond length. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent GeO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–48°. 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 (1.93 Å) Ge–O bond length. In the fourth Ge4+ site, Ge4+ is bonded to six equivalent O2- atoms to form corner-sharing GeO6 octahedra. All Ge–O bond lengths are 1.95 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Rb1+ and two Ge4+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Rb1+ and two Ge4+ atoms. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Rb1+ and two equivalent Ge4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Rb1+ and two Ge4+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Rb1+ and two Ge4+ atoms.