Materials Data on Ca12Be17O29 by Materials Project
Ca12Be17O29 crystallizes in the cubic F-43m space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 pentagonal pyramids that share corners with four equivalent CaO6 pentagonal pyramids, corners with two equivalent BeO4 tetrahedra, corners with two equivalent BeO4 trigonal pyramids, and edges with three BeO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.35–2.38 Å. In the second Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.46 Å) and four longer (2.54 Å) Ca–O bond lengths. There are five inequivalent Be2+ sites. In the first Be2+ site, Be2+ is bonded to four O2- atoms to form distorted BeO4 trigonal pyramids that share corners with three equivalent CaO6 pentagonal pyramids, a cornercorner with one BeO4 tetrahedra, corners with three equivalent BeO4 trigonal pyramids, and edges with three equivalent BeO4 tetrahedra. There is three shorter (1.56 Å) and one longer (2.26 Å) Be–O bond length. In the second Be2+ site, Be2+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All Be–O bond lengths are 1.55 Å. In the third Be2+ site, Be2+ is bonded to four O2- atoms to form BeO4 tetrahedra that share corners with three equivalent CaO6 pentagonal pyramids, corners with three equivalent BeO4 tetrahedra, a cornercorner with one BeO4 trigonal pyramid, and edges with three equivalent BeO4 trigonal pyramids. There is three shorter (1.62 Å) and one longer (1.85 Å) Be–O bond length. In the fourth Be2+ site, Be2+ is bonded to four equivalent O2- atoms to form BeO4 tetrahedra that share corners with four equivalent BeO4 tetrahedra and edges with six equivalent CaO6 pentagonal pyramids. All Be–O bond lengths are 1.69 Å. In the fifth Be2+ site, Be2+ is bonded to four O2- atoms to form BeO4 tetrahedra that share a cornercorner with one BeO4 tetrahedra and edges with three equivalent CaO6 pentagonal pyramids. There is three shorter (1.66 Å) and one longer (1.68 Å) Be–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to three Ca2+ and two Be2+ atoms to form a mixture of distorted edge and corner-sharing OCa3Be2 trigonal bipyramids. In the second O2- site, O2- is bonded in a distorted body-centered cubic geometry to eight Be2+ atoms. In the third O2- site, O2- is bonded to three Ca2+ and two Be2+ atoms to form a mixture of distorted edge and corner-sharing OCa3Be2 trigonal bipyramids. In the fourth O2- site, O2- is bonded to three equivalent Ca2+ and two Be2+ atoms to form a mixture of edge and corner-sharing OCa3Be2 trigonal bipyramids.