DOI: 10.17188/1692934
title: Materials Data on K2Ce2Fe4O11 by Materials Project

description: K2Ce2Fe4O11 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form distorted KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with four FeO6 octahedra, and faces with four FeO5 trigonal bipyramids. There are a spread of K–O bond distances ranging from 2.77–3.25 Å. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form distorted KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, faces with four KO12 cuboctahedra, faces with four FeO6 octahedra, and faces with four FeO5 trigonal bipyramids. There are a spread of K–O bond distances ranging from 2.77–3.26 Å. There are two inequivalent Ce4+ sites. In the first Ce4+ site, Ce4+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ce–O bond distances ranging from 2.45–2.70 Å. In the second Ce4+ site, Ce4+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ce–O bond distances ranging from 2.45–2.69 Å. There are four inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to five O2- atoms to form distorted FeO5 trigonal bipyramids that share corners with three FeO6 octahedra, corners with two equivalent FeO5 trigonal bipyramids, and faces with four KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of Fe–O bond distances ranging from 1.88–2.07 Å. In the second Fe3+ site, Fe3+ is bonded to five O2- atoms to form distorted FeO5 trigonal bipyramids that share corners with three FeO6 octahedra, corners with two equivalent FeO5 trigonal bipyramids, and faces with four KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of Fe–O bond distances ranging from 1.88–2.07 Å. In the third Fe3+ site, Fe3+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with three FeO6 octahedra, corners with three FeO5 trigonal bipyramids, and faces with four KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–18°. There are a spread of Fe–O bond distances ranging from 1.95–2.14 Å. In the fourth Fe3+ site, Fe3+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with three FeO6 octahedra, corners with three FeO5 trigonal bipyramids, and faces with four KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–18°. There are a spread of Fe–O bond distances ranging from 1.95–2.13 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, two equivalent Ce4+, and two Fe3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, two equivalent Ce4+, and two Fe3+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, two equivalent Ce4+, and two Fe3+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, two equivalent Ce4+, and two Fe3+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two K1+, two Ce4+, and two equivalent Fe3+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two K1+, two Ce4+, and two equivalent Fe3+ atoms. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to two K1+, two Ce4+, and two equivalent Fe3+ atoms. In the eighth O2- site, O2- is bonded in a 6-coordinate geometry to two K1+, two Ce4+, and two equivalent Fe3+ atoms. In the ninth O2- site, O2- is bonded to four K1+ and two Fe3+ atoms to form a mixture of distorted edge and corner-sharing OK4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the tenth O2- site, O2- is bonded to four K1+ and two Fe3+ atoms to form a mixture of distorted edge and corner-sharing OK4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to four Ce4+ and two Fe3+ atoms.