Materials Data on Ca9Zn4Sb9 by Materials Project

Abstract

Ca9Zn4Sb9 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are five inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six Sb+2.89- atoms to form CaSb6 octahedra that share corners with eight CaSb6 octahedra, corners with six ZnSb4 tetrahedra, edges with two equivalent CaSb6 octahedra, edges with four equivalent CaSb5 square pyramids, edges with two equivalent ZnSb4 tetrahedra, and faces with two equivalent CaSb6 octahedra. The corner-sharing octahedra tilt angles range from 41–49°. There are two shorter (3.26 Å) and four longer (3.33 Å) Ca–Sb bond lengths. In the second Ca2+ site, Ca2+ is bonded to five Sb+2.89- atoms to form distorted CaSb5 square pyramids that share corners with eight CaSb6 octahedra, edges with four CaSb6 octahedra, edges with two equivalent CaSb5 square pyramids, and edges with four ZnSb4 tetrahedra. The corner-sharing octahedra tilt angles range from 35–50°. There are a spread of Ca–Sb bond distances ranging from 3.16–3.24 Å. In the third Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five Sb+2.89- atoms. There are a spread of Ca–Sb bond distances ranging from 3.13–3.25 Å. In the fourth Ca2+ site, Ca2+ is bonded to six Sb+2.89- atoms to form CaSb6 octahedra that share corners with six CaSb6 octahedra, corners with four equivalent CaSb5 square pyramids, corners with two equivalent ZnSb4 tetrahedra, edges with four CaSb6 octahedra, edges with two equivalent CaSb5 square pyramids, and edges with four equivalent ZnSb4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–54°. There are a spread of Ca–Sb bond distances ranging from 3.18–3.38 Å. In the fifth Ca2+ site, Ca2+ is bonded to six Sb+2.89- atoms to form CaSb6 octahedra that share corners with five CaSb6 octahedra, corners with four equivalent CaSb5 square pyramids, corners with six ZnSb4 tetrahedra, edges with four CaSb6 octahedra, an edgeedge with one ZnSb4 tetrahedra, a faceface with one CaSb6 octahedra, and a faceface with one ZnSb4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–54°. There are a spread of Ca–Sb bond distances ranging from 3.24–3.48 Å. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four Sb+2.89- atoms to form ZnSb4 tetrahedra that share corners with seven CaSb6 octahedra, corners with four ZnSb4 tetrahedra, an edgeedge with one CaSb6 octahedra, edges with two equivalent CaSb5 square pyramids, and a faceface with one CaSb6 octahedra. The corner-sharing octahedra tilt angles range from 34–60°. There are a spread of Zn–Sb bond distances ranging from 2.71–2.97 Å. In the second Zn2+ site, Zn2+ is bonded to four Sb+2.89- atoms to form ZnSb4 tetrahedra that share corners with four CaSb6 octahedra, corners with three ZnSb4 tetrahedra, edges with five CaSb6 octahedra, and edges with two equivalent CaSb5 square pyramids. The corner-sharing octahedra tilt angles range from 21–54°. There are a spread of Zn–Sb bond distances ranging from 2.72–2.85 Å. There are five inequivalent Sb+2.89- sites. In the first Sb+2.89- site, Sb+2.89- is bonded in a 7-coordinate geometry to five Ca2+ and two equivalent Zn2+ atoms. In the second Sb+2.89- site, Sb+2.89- is bonded to six Ca2+ and one Zn2+ atom to form a mixture of distorted edge and corner-sharing SbCa6Zn pentagonal bipyramids. In the third Sb+2.89- site, Sb+2.89- is bonded in a 8-coordinate geometry to six Ca2+ and two Zn2+ atoms. In the fourth Sb+2.89- site, Sb+2.89- is bonded in a distorted body-centered cubic geometry to six Ca2+ and two equivalent Zn2+ atoms. In the fifth Sb+2.89- site, Sb+2.89- is bonded in a 7-coordinate geometry to five Ca2+ and two equivalent Zn2+ atoms.