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 five O2- atoms. There are four shorter (2.68 Å) and one longer (3.23 Å) Rb–O bond lengths. Li1+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Li–O bond lengths are 2.08 Å. There are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with four equivalent MgO5 square pyramids, edges with four equivalent MgO6 octahedra, and edges with four equivalent MgO5 square pyramids. There are four shorter (2.07 Å) and one longer (2.13 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with four equivalent MgO6 octahedra and edges with eight MgO5 square pyramids. The corner-sharing octahedral tilt angles are 9°. There are a spread of Mg–O bond distances ranging from 2.02–2.46 Å. In the third Mg2+ site, Mg2+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Mg–O bond distances ranging from 1.90–2.69 Å. In the fourth Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with four equivalent MgO5 square pyramids, edges with two equivalent MgO6 octahedra, and edges with six MgO5 square pyramids. There are a spread of Mg–O bond distances ranging from 2.07–2.13 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 square pyramids that share corners with four equivalent OMg5 square pyramids and edges with eight ORbMg5 octahedra. In the second O2- site, O2- is bonded to five Mg2+ atoms to form distorted OMg5 trigonal bipyramids that share a cornercorner with one ORbMg5 octahedra, corners with eight OMg5 trigonal bipyramids, and edges with four equivalent OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form distorted ORbMg5 octahedra that share corners with four equivalent ORbMg5 octahedra, corners with five OMg5 trigonal bipyramids, edges with four equivalent OMg6 octahedra, and edges with four equivalent OMg5 square pyramids. The corner-sharing octahedral tilt angles are 9°. In the fourth O2- site, O2- is bonded to two equivalent Rb1+, two equivalent Li1+, and one Mg2+ atom to form distorted ORb2Li2Mg trigonal bipyramids that share corners with three ORbMg5 octahedra, corners with six OMg5 trigonal bipyramids, and edges with four equivalent ORb2Li2Mg trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–51°. In the fifth O2- site, O2- is bonded to six Mg2+ atoms to form distorted OMg6 octahedra that share corners with four equivalent OMg6 octahedra, a cornercorner with one ORb2Li2Mg trigonal bipyramid, edges with six ORbMg5 octahedra, edges with two equivalent OMg5 square pyramids, and edges with two equivalent OMg5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 5–9°.