DOI: 10.17188/1656061
title: Materials Data on KTb2F7 by Materials Project

description: KTb2F7 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 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.68–2.95 Å. In the second 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 2.69–2.78 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 2.70–2.77 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 2.70–2.96 Å. There are five inequivalent Tb3+ sites. In the first Tb3+ site, Tb3+ is bonded in a body-centered cubic geometry to eight F1- atoms. There are a spread of Tb–F bond distances ranging from 2.23–2.46 Å. In the second Tb3+ site, Tb3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Tb–F bond distances ranging from 2.23–2.43 Å. In the third Tb3+ site, Tb3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Tb–F bond distances ranging from 2.23–2.40 Å. In the fourth Tb3+ site, Tb3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Tb–F bond distances ranging from 2.24–2.46 Å. In the fifth Tb3+ site, Tb3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Tb–F bond distances ranging from 2.21–2.44 Å. There are nineteen inequivalent F1- sites. In the first F1- site, F1- is bonded to one K1+ and three Tb3+ atoms to form a mixture of distorted edge and corner-sharing FKTb3 tetrahedra. In the second F1- site, F1- is bonded to two K1+ and two Tb3+ atoms to form distorted FK2Tb2 tetrahedra that share corners with ten FK2Tb2 tetrahedra and edges with four FKTb3 tetrahedra. In the third F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Tb3+ atoms. In the fourth F1- site, F1- is bonded to two K1+ and two equivalent Tb3+ atoms to form distorted FK2Tb2 tetrahedra that share corners with seven FKTb3 tetrahedra and edges with four FK2Tb2 tetrahedra. In the fifth F1- site, F1- is bonded to two K1+ and two equivalent Tb3+ atoms to form distorted FK2Tb2 tetrahedra that share corners with seven FKTb3 tetrahedra and edges with six FK2Tb2 tetrahedra. In the sixth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Tb3+ atoms. In the seventh F1- site, F1- is bonded to two K1+ and two equivalent Tb3+ atoms to form distorted FK2Tb2 tetrahedra that share corners with seven FKTb3 tetrahedra and edges with four FK2Tb2 tetrahedra. In the eighth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Tb3+ atoms. In the ninth F1- site, F1- is bonded to one K1+ and three Tb3+ atoms to form a mixture of distorted edge and corner-sharing FKTb3 tetrahedra. In the tenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Tb3+ atoms. In the eleventh F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Tb3+ atoms. In the twelfth F1- site, F1- is bonded in a 4-coordinate geometry to one K1+ and three Tb3+ atoms. In the thirteenth F1- site, F1- is bonded in a 2-coordinate geometry to one K1+ and two Tb3+ atoms. In the fourteenth F1- site, F1- is bonded in a 2-coordinate geometry to one K1+ and two Tb3+ atoms. In the fifteenth F1- site, F1- is bonded to one K1+ and three Tb3+ atoms to form FKTb3 tetrahedra that share corners with six FK2Tb2 tetrahedra and edges with three FKTb3 tetrahedra. In the sixteenth F1- site, F1- is bonded to two K1+ and two equivalent Tb3+ atoms to form a mixture of distorted edge and corner-sharing FK2Tb2 tetrahedra. In the seventeenth F1- site, F1- is bonded in a 4-coordinate geometry to one K1+ and three Tb3+ atoms. In the eighteenth F1- site, F1- is bonded to two K1+ and two Tb3+ atoms to form distorted FK2Tb2 tetrahedra that share corners with ten FKTb3 tetrahedra and edges with four FK2Tb2 tetrahedra. In the nineteenth F1- site, F1- is bonded to one K1+ and three Tb3+ atoms to form a mixture of distorted edge and corner-sharing FKTb3 tetrahedra.