Materials Data on K3TaO2F7 by Materials Project
K3TaO2F7 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are three inequivalent K sites. In the first K site, K is bonded in a 6-coordinate geometry to six F atoms. There are a spread of K–F bond distances ranging from 2.60–3.13 Å. In the second K site, K is bonded in a 8-coordinate geometry to one O and seven F atoms. The K–O bond length is 2.97 Å. There are a spread of K–F bond distances ranging from 2.49–3.13 Å. In the third K site, K is bonded in a 6-coordinate geometry to one O and five F atoms. The K–O bond length is 3.02 Å. There are a spread of K–F bond distances ranging from 2.48–2.92 Å. Ta is bonded in a distorted pentagonal bipyramidal geometry to two O and five F atoms. Both Ta–O bond lengths are 2.12 Å. There are a spread of Ta–F bond distances ranging from 1.92–1.96 Å. There are two inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one K, one Ta, and one O atom. The O–O bond length is 1.37 Å. In the second O site, O is bonded in a 3-coordinate geometry to one K, one Ta, and one O atom. There are seven inequivalent F sites. In the first F site, F is bonded in a distorted single-bond geometry to two K and one Ta atom. In the second F site, F is bonded in a distorted single-bond geometry to two K and one Ta atom. In the third F site, F is bonded in a distorted single-bond geometry to two K and one Ta atom. In the fourth F site, F is bonded in a distorted rectangular see-saw-like geometry to four K atoms. In the fifth F site, F is bonded to four K atoms to form distorted edge-sharing FK4 tetrahedra. In the sixth F site, F is bonded in a distorted trigonal non-coplanar geometry to two K and one Ta atom. In the seventh F site, F is bonded in a distorted single-bond geometry to two K and one Ta atom.