DOI: 10.17188/1733646
title: Materials Data on Ca21(Zn2Sb9)2 by Materials Project

description: Ca21Zn4Sb18 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are twelve inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six Sb+2.78- atoms to form distorted CaSb6 octahedra that share corners with eight CaSb6 octahedra, corners with two CaSb7 pentagonal bipyramids, corners with two ZnSb4 tetrahedra, edges with four CaSb6 octahedra, edges with two ZnSb4 tetrahedra, faces with two CaSb6 octahedra, and a faceface with one CaSb7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 33–61°. There are a spread of Ca–Sb bond distances ranging from 3.05–3.36 Å. In the second Ca2+ site, Ca2+ is bonded to six Sb+2.78- atoms to form distorted CaSb6 octahedra that share corners with nine CaSb6 octahedra, corners with two CaSb7 pentagonal bipyramids, corners with two ZnSb4 tetrahedra, edges with three CaSb6 octahedra, an edgeedge with one ZnSb4 tetrahedra, faces with three CaSb6 octahedra, a faceface with one CaSb7 pentagonal bipyramid, and a faceface with one ZnSb4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–53°. There are a spread of Ca–Sb bond distances ranging from 3.14–3.47 Å. In the third Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six Sb+2.78- atoms. There are a spread of Ca–Sb bond distances ranging from 3.13–3.76 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven Sb+2.78- atoms. There are a spread of Ca–Sb bond distances ranging from 3.12–3.87 Å. In the fifth Ca2+ site, Ca2+ is bonded to six Sb+2.78- atoms to form CaSb6 octahedra that share corners with ten CaSb6 octahedra, a cornercorner with one CaSb7 pentagonal bipyramid, corners with three ZnSb4 tetrahedra, edges with two equivalent CaSb6 octahedra, faces with four CaSb6 octahedra, and faces with two CaSb7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 31–61°. There are a spread of Ca–Sb bond distances ranging from 3.12–3.38 Å. In the sixth Ca2+ site, Ca2+ is bonded to six Sb+2.78- atoms to form distorted CaSb6 octahedra that share corners with nine CaSb6 octahedra, corners with four CaSb7 pentagonal bipyramids, a cornercorner with one ZnSb4 tetrahedra, edges with four CaSb6 octahedra, an edgeedge with one ZnSb4 tetrahedra, faces with two CaSb6 octahedra, a faceface with one CaSb7 pentagonal bipyramid, and a faceface with one ZnSb4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–75°. There are a spread of Ca–Sb bond distances ranging from 3.08–3.64 Å. In the seventh Ca2+ site, Ca2+ is bonded to six Sb+2.78- atoms to form distorted CaSb6 octahedra that share corners with eight CaSb6 octahedra, corners with two CaSb7 pentagonal bipyramids, corners with four ZnSb4 tetrahedra, edges with three CaSb6 octahedra, an edgeedge with one ZnSb4 tetrahedra, faces with three CaSb6 octahedra, and a faceface with one CaSb7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 34–71°. There are a spread of Ca–Sb bond distances ranging from 3.22–3.52 Å. In the eighth Ca2+ site, Ca2+ is bonded to six Sb+2.78- atoms to form distorted CaSb6 octahedra that share corners with eight CaSb6 octahedra, a cornercorner with one CaSb7 pentagonal bipyramid, corners with three ZnSb4 tetrahedra, edges with four CaSb6 octahedra, an edgeedge with one ZnSb4 tetrahedra, faces with two CaSb6 octahedra, and faces with two CaSb7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 35–51°. There are a spread of Ca–Sb bond distances ranging from 3.11–3.47 Å. In the ninth Ca2+ site, Ca2+ is bonded to six Sb+2.78- atoms to form distorted CaSb6 octahedra that share corners with nine CaSb6 octahedra, corners with three CaSb7 pentagonal bipyramids, a cornercorner with one ZnSb4 tetrahedra, edges with three CaSb6 octahedra, an edgeedge with one ZnSb4 tetrahedra, faces with four CaSb6 octahedra, and faces with two CaSb7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 31–75°. There are a spread of Ca–Sb bond distances ranging from 3.10–3.40 Å. In the tenth Ca2+ site, Ca2+ is bonded to seven Sb+2.78- atoms to form distorted CaSb7 pentagonal bipyramids that share corners with twelve CaSb6 octahedra, a cornercorner with one CaSb7 pentagonal bipyramid, corners with two ZnSb4 tetrahedra, edges with two CaSb7 pentagonal bipyramids, faces with six CaSb6 octahedra, and faces with two equivalent ZnSb4 tetrahedra. The corner-sharing octahedra tilt angles range from 38–56°. There are a spread of Ca–Sb bond distances ranging from 3.28–3.59 Å. In the eleventh Ca2+ site, Ca2+ is bonded to seven Sb+2.78- atoms to form CaSb7 pentagonal bipyramids that share corners with ten CaSb6 octahedra, a cornercorner with one CaSb7 pentagonal bipyramid, a cornercorner with one ZnSb4 tetrahedra, edges with two CaSb7 pentagonal bipyramids, an edgeedge with one ZnSb4 tetrahedra, faces with six CaSb6 octahedra, and faces with two equivalent ZnSb4 tetrahedra. The corner-sharing octahedra tilt angles range from 38–53°. There are a spread of Ca–Sb bond distances ranging from 3.31–3.61 Å. In the twelfth Ca2+ site, Ca2+ is bonded to seven Sb+2.78- atoms to form distorted CaSb7 pentagonal bipyramids that share corners with eight CaSb6 octahedra, corners with two CaSb7 pentagonal bipyramids, corners with two equivalent ZnSb4 tetrahedra, edges with two CaSb7 pentagonal bipyramids, an edgeedge with one ZnSb4 tetrahedra, and faces with eight CaSb6 octahedra. The corner-sharing octahedra tilt angles range from 31–45°. There are a spread of Ca–Sb bond distances ranging from 3.06–3.73 Å. There are three inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four Sb+2.78- atoms to form ZnSb4 tetrahedra that share corners with eight CaSb6 octahedra, a cornercorner with one CaSb7 pentagonal bipyramid, a cornercorner with one ZnSb4 tetrahedra, edges with five CaSb6 octahedra, an edgeedge with one ZnSb4 tetrahedra, and faces with two CaSb7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 33–57°. There are a spread of Zn–Sb bond distances ranging from 2.74–2.86 Å. In the second Zn2+ site, Zn2+ is bonded to four Sb+2.78- atoms to form ZnSb4 tetrahedra that share corners with eight CaSb6 octahedra, a cornercorner with one CaSb7 pentagonal bipyramid, corners with two equivalent ZnSb4 tetrahedra, edges with two equivalent CaSb6 octahedra, an edgeedge with one CaSb7 pentagonal bipyramid, an edgeedge with one ZnSb4 tetrahedra, and faces with two equivalent CaSb6 octahedra. The corner-sharing octahedra tilt angles range from 44–96°. There are a spread of Zn–Sb bond distances ranging from 2.74–2.79 Å. In the third Zn2+ site, Zn2+ is bonded to four Sb+2.78- atoms to form ZnSb4 tetrahedra that share corners with eight CaSb6 octahedra, corners with two CaSb7 pentagonal bipyramids, edges with two equivalent CaSb6 octahedra, an edgeedge with one CaSb7 pentagonal bipyramid, an edgeedge with one ZnSb4 tetrahedra, and faces with two equivalent CaSb6 octahedra. The corner-sharing octahedra tilt angles range from 39–61°. There are two shorter (2.79 Å) and two longer (2.81 Å) Zn–Sb bond lengths. There are fourteen inequivalent Sb+2.78- sites. In the first Sb+2.78- site, Sb+2.78- is bonded in a 9-coordinate geometry to seven Ca2+ and two equivalent Zn2+ atoms. In the second Sb+2.78- site, Sb+2.78- is bonded in a 9-coordinate geometry to eight Ca2+ and one Zn2+ atom. In the third Sb+2.78- site, Sb+2.78- is bonded in a 8-coordinate geometry to eight Ca2+ atoms. In the fourth Sb+2.78- site, Sb+2.78- is bonded in a 8-coordinate geometry to eight Ca2+ atoms. In the fifth Sb+2.78- site, Sb+2.78- is bonded in a 2-coordinate geometry to seven Ca2+ and one Sb+2.78- atom. The Sb–Sb bond length is 2.89 Å. In the sixth Sb+2.78- site, Sb+2.78- is bonded in a 7-coordinate geometry to five Ca2+, one Zn2+, and one Sb+2.78- atom. The Sb–Sb bond length is 2.88 Å. In the seventh Sb+2.78- site, Sb+2.78- is bonded in a 2-coordinate geometry to eight Ca2+ and one Sb+2.78- atom. The Sb–Sb bond length is 2.97 Å. In the eighth Sb+2.78- site, Sb+2.78- is bonded in a 9-coordinate geometry to eight Ca2+ and one Sb+2.78- atom. The Sb–Sb bond length is 2.97 Å. In the ninth Sb+2.78- site, Sb+2.78- is bonded in a 8-coordinate geometry to eight Ca2+ atoms. In the tenth Sb+2.78- site, Sb+2.78- is bonded in a 9-coordinate geometry to eight Ca2+ and one Zn2+ atom. In the eleventh Sb+2.78- site, Sb+2.78- is bonded in a 8-coordinate geometry to seven Ca2+ and one Zn2+ atom. In the twelfth Sb+2.78- site, Sb+2.78- is bonded in a 8-coordinate geometry to six Ca2+ and two Zn2+ atoms. In the thirteenth Sb+2.78- site, Sb+2.78- is bonded in a 9-coordinate geometry to six Ca2+ and three Zn2+ atoms. In the fourteenth Sb+2.78- site, Sb+2.78- is bonded in a 9-coordinate geometry to eight Ca2+ and one Zn2+ atom.