Materials Data on Sr11(CdSb2)6 by Materials Project
Sr11Cd6Sb12 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are six inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a distorted hexagonal planar geometry to six Sb+2.83- atoms. There are a spread of Sr–Sb bond distances ranging from 3.43–3.61 Å. In the second Sr2+ site, Sr2+ is bonded to six Sb+2.83- atoms to form SrSb6 octahedra that share corners with seven SrSb6 octahedra, corners with two equivalent SrSb5 trigonal bipyramids, corners with two equivalent CdSb4 trigonal pyramids, edges with two equivalent SrSb6 octahedra, edges with four CdSb4 tetrahedra, a faceface with one SrSb6 octahedra, and a faceface with one CdSb4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 33–48°. There are a spread of Sr–Sb bond distances ranging from 3.30–3.47 Å. In the third Sr2+ site, Sr2+ is bonded to six Sb+2.83- atoms to form SrSb6 octahedra that share corners with six SrSb6 octahedra, corners with four equivalent CdSb4 tetrahedra, corners with two equivalent SrSb5 trigonal bipyramids, corners with three equivalent CdSb4 trigonal pyramids, edges with two equivalent SrSb6 octahedra, edges with two equivalent CdSb4 tetrahedra, edges with three equivalent SrSb5 trigonal bipyramids, and faces with two SrSb6 octahedra. The corner-sharing octahedra tilt angles range from 33–56°. There are a spread of Sr–Sb bond distances ranging from 3.32–3.56 Å. In the fourth Sr2+ site, Sr2+ is bonded to six Sb+2.83- atoms to form SrSb6 octahedra that share corners with seven SrSb6 octahedra, corners with two equivalent CdSb4 tetrahedra, corners with four equivalent SrSb5 trigonal bipyramids, corners with two equivalent CdSb4 trigonal pyramids, edges with four equivalent SrSb6 octahedra, an edgeedge with one SrSb5 trigonal bipyramid, edges with three equivalent CdSb4 trigonal pyramids, and faces with two SrSb6 octahedra. The corner-sharing octahedra tilt angles range from 32–56°. There are a spread of Sr–Sb bond distances ranging from 3.43–3.63 Å. In the fifth Sr2+ site, Sr2+ is bonded to five Sb+2.83- atoms to form distorted SrSb5 trigonal bipyramids that share corners with eight SrSb6 octahedra, corners with two equivalent CdSb4 tetrahedra, a cornercorner with one CdSb4 trigonal pyramid, edges with four SrSb6 octahedra, an edgeedge with one CdSb4 tetrahedra, edges with four equivalent SrSb5 trigonal bipyramids, and edges with two equivalent CdSb4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 25–72°. There are a spread of Sr–Sb bond distances ranging from 3.31–3.65 Å. In the sixth Sr2+ site, Sr2+ is bonded to six Sb+2.83- atoms to form SrSb6 octahedra that share corners with eight SrSb6 octahedra, corners with four equivalent CdSb4 tetrahedra, edges with two equivalent SrSb6 octahedra, edges with four equivalent CdSb4 tetrahedra, and faces with two equivalent SrSb6 octahedra. The corner-sharing octahedra tilt angles range from 32–50°. There are two shorter (3.43 Å) and four longer (3.46 Å) Sr–Sb bond lengths. There are three inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four Sb+2.83- atoms to form CdSb4 tetrahedra that share corners with six SrSb6 octahedra, corners with four CdSb4 tetrahedra, and edges with four SrSb6 octahedra. The corner-sharing octahedra tilt angles range from 43–68°. There are a spread of Cd–Sb bond distances ranging from 2.83–3.32 Å. In the second Cd2+ site, Cd2+ is bonded to four Sb+2.83- atoms to form CdSb4 tetrahedra that share corners with two equivalent SrSb6 octahedra, corners with four CdSb4 tetrahedra, corners with two equivalent SrSb5 trigonal bipyramids, corners with two equivalent CdSb4 trigonal pyramids, edges with four SrSb6 octahedra, and an edgeedge with one SrSb5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 44°. There are a spread of Cd–Sb bond distances ranging from 2.87–3.06 Å. In the third Cd2+ site, Cd2+ is bonded to four Sb+2.83- atoms to form CdSb4 trigonal pyramids that share corners with seven SrSb6 octahedra, corners with two equivalent CdSb4 tetrahedra, a cornercorner with one SrSb5 trigonal bipyramid, corners with two equivalent CdSb4 trigonal pyramids, edges with three equivalent SrSb6 octahedra, edges with two equivalent SrSb5 trigonal bipyramids, and a faceface with one SrSb6 octahedra. The corner-sharing octahedra tilt angles range from 27–47°. There are a spread of Cd–Sb bond distances ranging from 2.91–3.14 Å. There are six inequivalent Sb+2.83- sites. In the first Sb+2.83- site, Sb+2.83- is bonded in a 8-coordinate geometry to six Sr2+ and two Cd2+ atoms. In the second Sb+2.83- site, Sb+2.83- is bonded in a 9-coordinate geometry to six Sr2+, two Cd2+, and one Sb+2.83- atom. The Sb–Sb bond length is 2.87 Å. In the third Sb+2.83- site, Sb+2.83- is bonded in a 8-coordinate geometry to seven Sr2+ and one Cd2+ atom. In the fourth Sb+2.83- site, Sb+2.83- is bonded in a 7-coordinate geometry to five Sr2+ and two equivalent Cd2+ atoms. In the fifth Sb+2.83- site, Sb+2.83- is bonded in a 7-coordinate geometry to four Sr2+ and three Cd2+ atoms. In the sixth Sb+2.83- site, Sb+2.83- is bonded in a 6-coordinate geometry to four Sr2+ and two equivalent Cd2+ atoms.