Materials Data on CaCe(FeSb3)8 by Materials Project
CaCe(FeSb3)8 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Ca2+ is bonded to twelve Sb+1.21- atoms to form CaSb12 cuboctahedra that share faces with eight FeSb6 octahedra. There are a spread of Ca–Sb bond distances ranging from 3.40–3.42 Å. Ce3+ is bonded to twelve Sb+1.21- atoms to form CeSb12 cuboctahedra that share faces with eight FeSb6 octahedra. There are a spread of Ce–Sb bond distances ranging from 3.41–3.43 Å. There are three inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six Sb+1.21- atoms to form FeSb6 octahedra that share corners with six FeSb6 octahedra, a faceface with one CaSb12 cuboctahedra, and a faceface with one CeSb12 cuboctahedra. The corner-sharing octahedra tilt angles range from 51–52°. There are a spread of Fe–Sb bond distances ranging from 2.54–2.57 Å. In the second Fe3+ site, Fe3+ is bonded to six Sb+1.21- atoms to form FeSb6 octahedra that share corners with six FeSb6 octahedra and faces with two equivalent CeSb12 cuboctahedra. The corner-sharing octahedra tilt angles range from 51–52°. There are a spread of Fe–Sb bond distances ranging from 2.54–2.56 Å. In the third Fe3+ site, Fe3+ is bonded to six Sb+1.21- atoms to form FeSb6 octahedra that share corners with six FeSb6 octahedra and faces with two equivalent CaSb12 cuboctahedra. The corner-sharing octahedral tilt angles are 52°. There are four shorter (2.55 Å) and two longer (2.56 Å) Fe–Sb bond lengths. There are eight inequivalent Sb+1.21- sites. In the first Sb+1.21- site, Sb+1.21- is bonded in a 2-coordinate geometry to one Ce3+, two equivalent Fe3+, and two Sb+1.21- atoms. There are one shorter (2.99 Å) and one longer (3.05 Å) Sb–Sb bond lengths. In the second Sb+1.21- site, Sb+1.21- is bonded in a 2-coordinate geometry to one Ca2+, two equivalent Fe3+, and two Sb+1.21- atoms. There are one shorter (2.97 Å) and one longer (3.05 Å) Sb–Sb bond lengths. In the third Sb+1.21- site, Sb+1.21- is bonded in a 2-coordinate geometry to one Ce3+, two equivalent Fe3+, and two Sb+1.21- atoms. In the fourth Sb+1.21- site, Sb+1.21- is bonded in a 2-coordinate geometry to one Ca2+, two equivalent Fe3+, and two Sb+1.21- atoms. In the fifth Sb+1.21- site, Sb+1.21- is bonded in a 2-coordinate geometry to one Ce3+, two Fe3+, and one Sb+1.21- atom. The Sb–Sb bond length is 3.04 Å. In the sixth Sb+1.21- site, Sb+1.21- is bonded in a 2-coordinate geometry to one Ca2+, two Fe3+, and two Sb+1.21- atoms. The Sb–Sb bond length is 2.97 Å. In the seventh Sb+1.21- site, Sb+1.21- is bonded in a 2-coordinate geometry to one Ca2+, two Fe3+, and two equivalent Sb+1.21- atoms. There are one shorter (2.98 Å) and one longer (3.04 Å) Sb–Sb bond lengths. In the eighth Sb+1.21- site, Sb+1.21- is bonded in a 2-coordinate geometry to one Ce3+ and two Fe3+ atoms.