Materials Data on RbLiMg6O7 by Materials Project

Abstract

RbLiMg6O7 crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. Rb1+ is bonded in a 5-coordinate geometry to four equivalent Mg2+ and five O2- atoms. All Rb–Mg bond lengths are 2.71 Å. There are four shorter (2.38 Å) and one longer (2.67 Å) Rb–O bond lengths. Li1+ is bonded to five O2- atoms to form distorted LiO5 square pyramids that share corners with four equivalent LiO5 square pyramids and edges with eight MgO6 octahedra. There are one shorter (1.81 Å) and four longer (2.33 Å) Li–O bond lengths. There are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with four equivalent MgO6 octahedra, and edges with four equivalent LiO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Mg–O bond distances ranging from 1.99–2.31 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Mg–O bond distances ranging from 1.99–2.31 Å. In the third Mg2+ site, Mg2+ is bonded in a distorted square co-planar geometry to two equivalent Rb1+ and four O2- atoms. There are a spread of Mg–O bond distances ranging from 1.90–2.30 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with four equivalent MgO6 octahedra, edges with eight MgO6 octahedra, and edges with two equivalent LiO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.07–2.30 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to one Rb1+, one Li1+, and four equivalent Mg2+ atoms to form distorted ORbLiMg4 octahedra that share corners with four equivalent ORbLiMg4 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with eight OLi2Mg4 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the third O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with twelve ORbLiMg4 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the fourth O2- site, O2- is bonded to two equivalent Li1+ and four Mg2+ atoms to form OLi2Mg4 octahedra that share corners with six OLi2Mg4 octahedra and edges with ten ORbLiMg4 octahedra. The corner-sharing octahedra tilt angles range from 0–17°. In the fifth O2- site, O2- is bonded to two equivalent Rb1+ and four Mg2+ atoms to form ORb2Mg4 octahedra that share corners with six OLi2Mg4 octahedra and edges with ten ORbLiMg4 octahedra. The corner-sharing octahedra tilt angles range from 0–29°.