DOE OSTI2020
KHo2F7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 5-coordinate geometry to five F1- atoms. There are a spread of K–F bond distances ranging from 2.68–2.76 Å. In the second K1+ site, K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.68–2.94 Å. In the third K1+ site, K1+ is bonded in a 5-coordinate geometry to five F1- atoms. There are a spread of K–F bond distances ranging from 2.67–2.75 Å. In the fourth K1+ site, K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.67–2.93 Å. There are five inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a body-centered cubic geometry to eight F1- atoms. There are a spread of Ho–F bond distances ranging from 2.21–2.44 Å. In the second Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Ho–F bond distances ranging from 2.21–2.42 Å. In the third Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Ho–F bond distances ranging from 2.18–2.43 Å. In the fourth Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Ho–F bond distances ranging from 2.21–2.44 Å. In the fifth Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Ho–F bond distances ranging from 2.21–2.37 Å. There are nineteen inequivalent F1- sites. In the first F1- site, F1- is bonded to two K1+ and two Ho3+ atoms to form a mixture of distorted edge and corner-sharing FK2Ho2 tetrahedra. In the second F1- site, F1- is bonded to two K1+ and two Ho3+ atoms to form distorted FK2Ho2 tetrahedra that share corners with ten FKHo3 tetrahedra and edges with four FK2Ho2 tetrahedra. In the third F1- site, F1- is bonded to one K1+ and three Ho3+ atoms to form distorted FKHo3 tetrahedra that share corners with eight FKHo3 tetrahedra and edges with three FK2Ho2 tetrahedra. In the fourth F1- site, F1- is bonded to two K1+ and two equivalent Ho3+ atoms to form distorted FK2Ho2 tetrahedra that share corners with seven FKHo3 tetrahedra and edges with four FK2Ho2 tetrahedra. In the fifth F1- site, F1- is bonded to two K1+ and two equivalent Ho3+ atoms to form distorted FK2Ho2 tetrahedra that share corners with seven FKHo3 tetrahedra and edges with six FK2Ho2 tetrahedra. In the sixth F1- site, F1- is bonded to one K1+ and three Ho3+ atoms to form a mixture of distorted edge and corner-sharing FKHo3 tetrahedra. In the seventh F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Ho3+ atoms. In the eighth F1- site, F1- is bonded to one K1+ and three Ho3+ atoms to form distorted FKHo3 tetrahedra that share corners with eight FKHo3 tetrahedra and edges with three FK2Ho2 tetrahedra. In the ninth F1- site, F1- is bonded to one K1+ and three Ho3+ atoms to form a mixture of edge and corner-sharing FKHo3 tetrahedra. In the tenth F1- site, F1- is bonded to two K1+ and two equivalent Ho3+ atoms to form distorted FK2Ho2 tetrahedra that share corners with seven FKHo3 tetrahedra and edges with six FK2Ho2 tetrahedra. In the eleventh F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Ho3+ atoms. In the twelfth F1- site, F1- is bonded in a 2-coordinate geometry to one K1+ and two Ho3+ atoms. In the thirteenth F1- site, F1- is bonded in a 2-coordinate geometry to one K1+ and two Ho3+ atoms. In the fourteenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Ho3+ atoms. In the fifteenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Ho3+ atoms. In the sixteenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Ho3+ atoms. In the seventeenth F1- site, F1- is bonded in a 4-coordinate geometry to one K1+ and three Ho3+ atoms. In the eighteenth F1- site, F1- is bonded to two K1+ and two equivalent Ho3+ atoms to form distorted FK2Ho2 tetrahedra that share corners with seven FKHo3 tetrahedra and edges with four FK2Ho2 tetrahedra. In the nineteenth F1- site, F1- is bonded in a 4-coordinate geometry to one K1+ and three Ho3+ atoms.