DOI: 10.17188/1654171
title: Materials Data on RbNaMg14O15 by Materials Project

description: RbNaMg14O15 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Rb1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Rb–O bond distances ranging from 2.52–2.72 Å. Na1+ is bonded to five O2- atoms to form distorted NaO5 trigonal bipyramids that share corners with four MgO5 square pyramids, corners with two equivalent NaO5 trigonal bipyramids, corners with three MgO5 trigonal bipyramids, and edges with four equivalent MgO5 square pyramids. There are a spread of Na–O bond distances ranging from 2.17–2.48 Å. There are ten inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with two equivalent MgO6 octahedra, a cornercorner with one NaO5 trigonal bipyramid, corners with four MgO5 trigonal bipyramids, edges with four equivalent MgO6 octahedra, and edges with four MgO5 square pyramids. The corner-sharing octahedral tilt angles are 10°. There are a spread of Mg–O bond distances ranging from 2.03–2.10 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 trigonal bipyramids, edges with six MgO6 octahedra, edges with two equivalent MgO5 square pyramids, and edges with four MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 2°. There are a spread of Mg–O bond distances ranging from 1.98–2.20 Å. In the third Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share a cornercorner with one MgO6 octahedra, corners with four equivalent MgO5 square pyramids, an edgeedge with one MgO6 octahedra, edges with two equivalent NaO5 trigonal bipyramids, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 11°. There are a spread of Mg–O bond distances ranging from 2.07–2.29 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, a cornercorner with one MgO5 square pyramid, edges with three MgO6 octahedra, edges with three MgO5 square pyramids, and edges with five MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 1–23°. There are a spread of Mg–O bond distances ranging from 2.02–2.44 Å. In the fifth Mg2+ site, Mg2+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.96 Å) and two longer (2.01 Å) Mg–O bond length. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, a cornercorner with one MgO5 trigonal bipyramid, edges with four MgO6 octahedra, edges with two equivalent MgO5 square pyramids, and edges with four equivalent MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 15°. There are a spread of Mg–O bond distances ranging from 1.97–2.34 Å. In the seventh Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with two equivalent MgO5 square pyramids, corners with two equivalent NaO5 trigonal bipyramids, corners with two equivalent MgO5 trigonal bipyramids, edges with two equivalent MgO6 octahedra, edges with four equivalent MgO5 square pyramids, and edges with two equivalent MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.10–2.19 Å. In the eighth Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share a cornercorner with one MgO6 octahedra, corners with two equivalent MgO5 square pyramids, corners with two equivalent MgO5 trigonal bipyramids, edges with four MgO6 octahedra, and edges with four equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.06–2.10 Å. In the ninth Mg2+ site, Mg2+ is bonded to five O2- atoms to form distorted MgO5 trigonal bipyramids that share a cornercorner with one MgO5 square pyramid, a cornercorner with one NaO5 trigonal bipyramid, corners with four MgO5 trigonal bipyramids, edges with five MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. There are a spread of Mg–O bond distances ranging from 1.94–2.32 Å. In the tenth Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with four equivalent MgO5 square pyramids, a cornercorner with one NaO5 trigonal bipyramid, a cornercorner with one MgO5 trigonal bipyramid, edges with three MgO6 octahedra, edges with two equivalent MgO5 square pyramids, and edges with three MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.07–2.17 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 square pyramids that share a cornercorner with one ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, corners with four ORb2Mg3 trigonal bipyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to one Na1+ and five Mg2+ atoms to form ONaMg5 octahedra that share corners with four ONaMg5 octahedra, corners with four ORbNaMg3 trigonal bipyramids, edges with two equivalent OMg6 octahedra, edges with four equivalent OMg5 square pyramids, and edges with two equivalent OMg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 4°. In the third O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form ORbMg5 octahedra that share corners with four ONaMg5 octahedra, a cornercorner with one OMg5 square pyramid, corners with four ORb2Mg3 trigonal bipyramids, edges with four OMg6 octahedra, and edges with four equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 1–4°. In the fourth 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 OMg5 square pyramid, a cornercorner with one OMg5 trigonal bipyramid, edges with three OMg6 octahedra, edges with two equivalent OMg5 square pyramids, and edges with four ONa2Mg3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 4–46°. In the fifth O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 square pyramids that share a cornercorner with one OMg6 octahedra, corners with four equivalent OMg5 square pyramids, edges with seven ONaMg5 octahedra, and an edgeedge with one OMg5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 1°. In the sixth O2- site, O2- is bonded to two equivalent Na1+ and three Mg2+ atoms to form distorted ONa2Mg3 trigonal bipyramids that share corners with two equivalent ONaMg5 octahedra, corners with four ORb2Mg3 trigonal bipyramids, edges with two equivalent OMg6 octahedra, and edges with four equivalent ORbNaMg3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 76°. In the seventh O2- site, O2- is bonded to two equivalent Rb1+ and three Mg2+ atoms to form distorted ORb2Mg3 trigonal bipyramids that share corners with three ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, corners with four ONa2Mg3 trigonal bipyramids, edges with two equivalent OMg6 octahedra, and edges with four equivalent ORbNaMg3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–57°. In the eighth O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 trigonal bipyramids that share corners with four OMg6 octahedra, corners with two equivalent OMg5 trigonal bipyramids, edges with six ONaMg5 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 12–82°. In the ninth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with two equivalent OMg6 octahedra, corners with three ORb2Mg3 trigonal bipyramids, edges with eight ORbMg5 octahedra, and edges with four OMg5 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the tenth O2- site, O2- is bonded to one Rb1+, one Na1+, and three Mg2+ atoms to form distorted ORbNaMg3 trigonal bipyramids that share corners with three ONaMg5 octahedra, a cornercorner with one OMg5 square pyramid, corners with four equivalent ORbNaMg3 trigonal bipyramids, edges with two equivalent OMg6 octahedra, and edges with four ORb2Mg3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 18–59°. In the eleventh O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with four equivalent OMg6 octahedra, a cornercorner with one ORbNaMg3 trigonal bipyramid, edges with six ONaMg5 octahedra, edges with three OMg5 square pyramids, and edges with two equivalent OMg5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 1–21°.