Materials Data on KCaV2F9 by Materials Project
KCaV2F9 crystallizes in the orthorhombic C222_1 space group. The structure is three-dimensional. there are two 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 2.89–3.17 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 2.90–3.18 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six F1- atoms to form distorted CaF6 octahedra that share corners with six VF6 octahedra. The corner-sharing octahedra tilt angles range from 23–61°. There are two shorter (2.19 Å) and four longer (2.42 Å) Ca–F bond lengths. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Ca–F bond distances ranging from 2.23–2.45 Å. There are three inequivalent V3+ sites. In the first V3+ site, V3+ is bonded to six F1- atoms to form VF6 octahedra that share corners with two equivalent CaF6 octahedra and corners with three VF6 octahedra. The corner-sharing octahedra tilt angles range from 30–61°. There are a spread of V–F bond distances ranging from 1.95–2.02 Å. In the second V3+ site, V3+ is bonded to six F1- atoms to form corner-sharing VF6 octahedra. The corner-sharing octahedra tilt angles range from 31–32°. There are a spread of V–F bond distances ranging from 1.95–2.03 Å. In the third V3+ site, V3+ is bonded to six F1- atoms to form VF6 octahedra that share a cornercorner with one CaF6 octahedra and corners with three VF6 octahedra. The corner-sharing octahedra tilt angles range from 23–32°. There are a spread of V–F bond distances ranging from 1.92–1.99 Å. There are fourteen inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent K1+, one Ca2+, and one V3+ atom. In the second F1- site, F1- is bonded in a 2-coordinate geometry to two K1+, one Ca2+, and one V3+ atom. In the third F1- site, F1- is bonded in a bent 150 degrees geometry to two V3+ atoms. In the fourth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+, one Ca2+, and one V3+ atom. In the fifth F1- site, F1- is bonded in a bent 150 degrees geometry to one Ca2+ and one V3+ atom. In the sixth F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent V3+ atoms. In the seventh F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent V3+ atoms. In the eighth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+, one Ca2+, and one V3+ atom. In the ninth F1- site, F1- is bonded in a 1-coordinate geometry to two K1+, one Ca2+, and one V3+ atom. In the tenth F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent K1+, one Ca2+, and one V3+ atom. In the eleventh F1- site, F1- is bonded in a 1-coordinate geometry to two K1+, one Ca2+, and one V3+ atom. In the twelfth F1- site, F1- is bonded in a bent 150 degrees geometry to two V3+ atoms. In the thirteenth F1- site, F1- is bonded in a 2-coordinate geometry to two K1+, one Ca2+, and one V3+ atom. In the fourteenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and two V3+ atoms.