Materials Data on K2Sn2OF6 by Materials Project
K2Sn2OF6 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to one O2- and six F1- atoms. The K–O bond length is 2.96 Å. There are a spread of K–F bond distances ranging from 2.66–2.91 Å. Sn3+ is bonded in a distorted rectangular see-saw-like geometry to four F1- atoms. There are a spread of Sn–F bond distances ranging from 2.04–2.20 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent O2- and four equivalent F1- atoms to form corner-sharing OO2F4 octahedra. The corner-sharing octahedral tilt angles are 0°. Both O–O bond lengths are 2.11 Å. All O–F bond lengths are 3.08 Å. In the second O2- site, O2- is bonded to four equivalent K1+ and two equivalent O2- atoms to form corner-sharing OK4O2 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to two equivalent K1+, one Sn3+, and one O2- atom. In the second F1- site, F1- is bonded in a 3-coordinate geometry to one K1+ and two equivalent Sn3+ atoms. In the third F1- site, F1- is bonded in a 1-coordinate geometry to three equivalent K1+ and one Sn3+ atom.