DOI: 10.17188/1706743
title: Materials Data on K6Ta3O8F13 by Materials Project

description: K6Ta3O8F13 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent K sites. In the first K site, K is bonded in a 9-coordinate geometry to one O and eight F atoms. The K–O bond length is 3.14 Å. There are a spread of K–F bond distances ranging from 2.71–3.09 Å. In the second K site, K is bonded in a 9-coordinate geometry to five O and four F atoms. There are a spread of K–O bond distances ranging from 2.77–3.26 Å. There are a spread of K–F bond distances ranging from 2.74–3.06 Å. In the third K site, K is bonded in a 7-coordinate geometry to two equivalent O and five F atoms. Both K–O bond lengths are 2.85 Å. There are a spread of K–F bond distances ranging from 2.66–2.79 Å. In the fourth K site, K is bonded in a 8-coordinate geometry to four O and four F atoms. There are a spread of K–O bond distances ranging from 2.83–3.06 Å. There are a spread of K–F bond distances ranging from 2.83–3.04 Å. There are three inequivalent Ta sites. In the first Ta site, Ta is bonded in a pentagonal bipyramidal geometry to two equivalent O and five F atoms. Both Ta–O bond lengths are 1.99 Å. There are a spread of Ta–F bond distances ranging from 1.93–2.03 Å. In the second Ta site, Ta is bonded to three O and four F atoms to form corner-sharing TaO3F4 pentagonal bipyramids. There is one shorter (1.94 Å) and two longer (2.03 Å) Ta–O bond length. There are a spread of Ta–F bond distances ranging from 1.98–2.03 Å. In the third Ta site, Ta is bonded to three O and four F atoms to form corner-sharing TaO3F4 pentagonal bipyramids. There is one shorter (1.92 Å) and two longer (2.03 Å) Ta–O bond length. There are a spread of Ta–F bond distances ranging from 1.97–2.03 Å. There are five inequivalent O sites. In the first O site, O is bonded in a 1-coordinate geometry to two K, one Ta, and one O atom. The O–O bond length is 1.50 Å. In the second O site, O is bonded in a 1-coordinate geometry to three K, one Ta, and one O atom. The O–O bond length is 1.48 Å. In the third O site, O is bonded in a 1-coordinate geometry to two K, one Ta, and one O atom. The O–O bond length is 1.45 Å. In the fourth O site, O is bonded in a linear geometry to two Ta atoms. In the fifth O site, O is bonded in a distorted trigonal non-coplanar geometry to three K atoms. There are ten inequivalent F sites. In the first F site, F is bonded in a distorted single-bond geometry to three K and one Ta atom. In the second F site, F is bonded to three K and one Ta atom to form distorted corner-sharing FK3Ta tetrahedra. In the third F site, F is bonded in a distorted single-bond geometry to one K and one Ta atom. In the fourth F site, F is bonded in a 4-coordinate geometry to three K and one Ta atom. In the fifth F site, F is bonded to three K and one Ta atom to form distorted corner-sharing FK3Ta tetrahedra. In the sixth F site, F is bonded in a trigonal non-coplanar geometry to two equivalent K and one Ta atom. In the seventh F site, F is bonded in a 1-coordinate geometry to two equivalent K and one Ta atom. In the eighth F site, F is bonded in a distorted trigonal non-coplanar geometry to two equivalent K and one Ta atom. In the ninth F site, F is bonded in a 1-coordinate geometry to three K and one Ta atom. In the tenth F site, F is bonded in a 4-coordinate geometry to three K and one Ta atom.