Materials Data on KRbGeO3 by Materials Project

RbKGeO3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Rb–O bond distances ranging from 2.93–3.27 Å. In the second Rb1+ site, Rb1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Rb–O bond distances ranging from 2.88–3.07 Å. There are two inequivalent K1+ sites. In the first 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 2.82–3.18 Å. In the second K1+ site, K1+ is bonded to five O2- atoms to form distorted KO5 square pyramids that share corners with two equivalent KO5 square pyramids, corners with five GeO4 tetrahedra, and edges with two equivalent KO5 square pyramids. There are a spread of K–O bond distances ranging from 2.63–2.89 Å. There are two 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 KO5 square pyramids and corners with two equivalent GeO4 tetrahedra. There is two shorter (1.74 Å) and two longer (1.84 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 three equivalent KO5 square pyramids and corners with two equivalent GeO4 tetrahedra. There are a spread of Ge–O bond distances ranging from 1.74–1.84 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to one Rb1+, four K1+, and one Ge4+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Rb1+, one K1+, and two Ge4+ atoms. In the third O2- site, O2- is bonded in a distorted single-bond geometry to four Rb1+, one K1+, and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to three Rb1+, two K1+, and one Ge4+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, three K1+, and one Ge4+ atom.