Materials Data on K3Ta4F15 by Materials Project
K3Ta4F15 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are six inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.68–3.15 Å. In the second K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.74–3.14 Å. In the third K1+ site, K1+ is bonded in a 3-coordinate geometry to three F1- atoms. There are one shorter (2.59 Å) and two longer (2.77 Å) K–F bond lengths. In the fourth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.67–3.21 Å. In the fifth K1+ site, K1+ is bonded in a distorted trigonal non-coplanar geometry to three F1- atoms. There are two shorter (2.50 Å) and one longer (2.66 Å) K–F bond lengths. In the sixth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.57–3.22 Å. There are eight inequivalent Ta3+ sites. In the first Ta3+ site, Ta3+ is bonded to six F1- atoms to form corner-sharing TaF6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Ta–F bond distances ranging from 1.96–2.07 Å. In the second Ta3+ site, Ta3+ is bonded to six F1- atoms to form corner-sharing TaF6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 17°. There are a spread of Ta–F bond distances ranging from 2.05–2.18 Å. In the third Ta3+ site, Ta3+ is bonded to six F1- atoms to form TaF6 pentagonal pyramids that share corners with two equivalent TaF6 pentagonal pyramids, a cornercorner with one TaF5 square pyramid, and a cornercorner with one TaF5 trigonal bipyramid. There are a spread of Ta–F bond distances ranging from 2.04–2.23 Å. In the fourth Ta3+ site, Ta3+ is bonded to five F1- atoms to form distorted TaF5 trigonal bipyramids that share a cornercorner with one TaF6 pentagonal pyramid, a cornercorner with one TaF5 square pyramid, and corners with two equivalent TaF5 trigonal bipyramids. There are a spread of Ta–F bond distances ranging from 2.01–2.21 Å. In the fifth Ta3+ site, Ta3+ is bonded to six F1- atoms to form corner-sharing TaF6 pentagonal pyramids. There are a spread of Ta–F bond distances ranging from 2.02–2.10 Å. In the sixth Ta3+ site, Ta3+ is bonded to five F1- atoms to form distorted TaF5 square pyramids that share a cornercorner with one TaF6 pentagonal pyramid, corners with two equivalent TaF5 square pyramids, and a cornercorner with one TaF5 trigonal bipyramid. There are a spread of Ta–F bond distances ranging from 2.06–2.19 Å. In the seventh Ta3+ site, Ta3+ is bonded to six F1- atoms to form corner-sharing TaF6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Ta–F bond distances ranging from 1.92–2.08 Å. In the eighth Ta3+ site, Ta3+ is bonded to six F1- atoms to form corner-sharing TaF6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 12°. There are a spread of Ta–F bond distances ranging from 2.03–2.18 Å. There are thirty inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted linear geometry to two Ta3+ atoms. In the second F1- site, F1- is bonded to three K1+ and one Ta3+ atom to form distorted corner-sharing FK3Ta tetrahedra. In the third F1- site, F1- is bonded in a linear geometry to two equivalent Ta3+ atoms. In the fourth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two equivalent Ta3+ atoms. In the fifth F1- site, F1- is bonded in an L-shaped geometry to two Ta3+ atoms. In the sixth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Ta3+ atoms. In the seventh F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Ta3+ atoms. In the eighth F1- site, F1- is bonded in a linear geometry to two equivalent Ta3+ atoms. In the ninth F1- site, F1- is bonded in a distorted trigonal planar geometry to two equivalent K1+ and one Ta3+ atom. In the tenth F1- site, F1- is bonded in a distorted L-shaped geometry to two equivalent K1+ and two Ta3+ atoms. In the eleventh F1- site, F1- is bonded in a water-like geometry to two Ta3+ atoms. In the twelfth F1- site, F1- is bonded to three K1+ and one Ta3+ atom to form distorted corner-sharing FK3Ta tetrahedra. In the thirteenth F1- site, F1- is bonded in a 3-coordinate geometry to two K1+ and one Ta3+ atom. In the fourteenth F1- site, F1- is bonded in a linear geometry to one K1+ and two equivalent Ta3+ atoms. In the fifteenth F1- site, F1- is bonded in a distorted linear geometry to one K1+ and two equivalent Ta3+ atoms. In the sixteenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two equivalent Ta3+ atoms. In the seventeenth F1- site, F1- is bonded in a distorted water-like geometry to two equivalent K1+ and two Ta3+ atoms. In the eighteenth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent K1+ and one Ta3+ atom. In the nineteenth F1- site, F1- is bonded in a 1-coordinate geometry to three K1+ and one Ta3+ atom. In the twentieth F1- site, F1- is bonded in a 4-coordinate geometry to three K1+ and one Ta3+ atom. In the twenty-first F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent K1+ and one Ta3+ atom. In the twenty-second F1- site, F1- is bonded in a single-bond geometry to one Ta3+ atom. In the twenty-third F1- site, F1- is bonded in a 3-coordinate geometry to two equivalent K1+ and one Ta3+ atom. In the twenty-fourth F1- site, F1- is bonded in a 1-coordinate geometry to three K1+ and one Ta3+ atom. In the twenty-fifth F1- site, F1- is bonded in a 1-coordinate geometry to three K1+ and one Ta3+ atom. In the twenty-sixth F1- site, F1- is bonded in a 4-coordinate geometry to two equivalent K1+ and two Ta3+ atoms. In the twenty-seventh F1- site, F1- is bonded in a distorted linear geometry to two Ta3+ atoms. In the twenty-eighth F1- site, F1- is bonded in a 3-coordinate geometry to two K1+ and one Ta3+ atom. In the twenty-ninth F1- site, F1- is bonded in a distorted L-shaped geometry to two equivalent K1+ and two Ta3+ atoms. In the thirtieth F1- site, F1- is bonded in a single-bond geometry to one Ta3+ atom.