Materials Data on CsKMg14O15 by Materials Project
CsKMg14O15 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Cs1+ is bonded in a 12-coordinate geometry to four O2- atoms. There are two shorter (2.58 Å) and two longer (2.61 Å) Cs–O bond lengths. K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.39–2.61 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 four MgO5 trigonal bipyramids and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.96–2.12 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, edges with two equivalent MgO6 octahedra, edges with four equivalent MgO5 square pyramids, and edges with four MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. There are two shorter (2.01 Å) and four longer (2.11 Å) Mg–O bond lengths. In the third Mg2+ site, Mg2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Mg–O bond distances ranging from 2.17–2.20 Å. In the fourth Mg2+ site, Mg2+ is bonded to five O2- atoms to form distorted MgO5 square pyramids that share a cornercorner with one MgO6 octahedra, corners with four equivalent MgO5 square pyramids, corners with three MgO5 trigonal bipyramids, and edges with three MgO6 octahedra. The corner-sharing octahedral tilt angles are 75°. There are a spread of Mg–O bond distances ranging from 2.13–2.25 Å. In the fifth 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 two equivalent MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 9°. There are a spread of Mg–O bond distances ranging from 2.02–2.37 Å. In the sixth Mg2+ site, Mg2+ is bonded in a distorted trigonal planar geometry to three O2- atoms. There are one shorter (1.95 Å) and two longer (2.07 Å) Mg–O bond lengths. In the seventh Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with three MgO6 octahedra, corners with two equivalent MgO5 square pyramids, corners with two equivalent MgO5 trigonal bipyramids, edges with two equivalent MgO6 octahedra, and edges with four equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–27°. There are a spread of Mg–O bond distances ranging from 2.10–2.14 Å. In the eighth Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, corners with two equivalent MgO5 trigonal bipyramids, and edges with six MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 12°. There are a spread of Mg–O bond distances ranging from 2.00–2.44 Å. In the ninth 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 1.92–2.21 Å. In the tenth Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with two equivalent MgO5 square pyramids, corners with five MgO5 trigonal bipyramids, edges with three MgO6 octahedra, and edges with two equivalent MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.01–2.20 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 trigonal bipyramids that share a cornercorner with one OKMg5 octahedra, corners with two equivalent OMg5 trigonal bipyramids, and edges with two equivalent OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to one K1+ and five Mg2+ atoms to form OKMg5 octahedra that share corners with two equivalent OKMg5 octahedra, corners with three OMg5 trigonal bipyramids, edges with two equivalent OMg6 octahedra, and edges with four equivalent OMg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 2°. In the third O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 trigonal bipyramids that share corners with two equivalent OKMg5 octahedra, corners with two equivalent OMg5 trigonal bipyramids, edges with two equivalent OMg6 octahedra, and edges with four equivalent OMg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 12°. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to five Mg2+ atoms. In the fifth O2- site, O2- is bonded to five Mg2+ atoms to form distorted OMg5 trigonal bipyramids that share a cornercorner with one OMg6 octahedra, corners with four equivalent OMg5 trigonal bipyramids, edges with three OMg6 octahedra, and edges with two equivalent OMg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 71°. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent K1+ and three Mg2+ atoms. In the seventh O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with two equivalent OMg6 octahedra and edges with four OMg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 14°. In the eighth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with two equivalent OMg6 octahedra, corners with two equivalent OMg5 trigonal bipyramids, edges with two equivalent OKMg5 octahedra, and edges with two equivalent OMg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. In the ninth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Cs1+ and three Mg2+ atoms. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to one K1+ and four Mg2+ atoms. In the eleventh O2- site, O2- is bonded in a 5-coordinate geometry to one Cs1+ and four Mg2+ atoms.