Materials Data on Cs2KTiO2F3 by Materials Project
Cs2KTiO2F3 crystallizes in the orthorhombic Fmm2 space group. The structure is three-dimensional. Cs1+ is bonded in a 8-coordinate geometry to two equivalent O2- and six F1- atoms. Both Cs–O bond lengths are 2.89 Å. There are a spread of Cs–F bond distances ranging from 3.06–3.49 Å. K1+ is bonded to two equivalent O2- and three F1- atoms to form distorted KO2F3 square pyramids that share corners with five equivalent TiO2F3 trigonal bipyramids. Both K–O bond lengths are 2.95 Å. There are one shorter (2.63 Å) and two longer (2.71 Å) K–F bond lengths. Ti4+ is bonded to two equivalent O2- and three F1- atoms to form TiO2F3 trigonal bipyramids that share corners with five equivalent KO2F3 square pyramids. Both Ti–O bond lengths are 1.76 Å. There are one shorter (2.00 Å) and two longer (2.07 Å) Ti–F bond lengths. O2- is bonded in a distorted single-bond geometry to two equivalent Cs1+, one K1+, and one Ti4+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 4-coordinate geometry to four equivalent Cs1+, one K1+, and one Ti4+ atom. In the second F1- site, F1- is bonded in a 2-coordinate geometry to four equivalent Cs1+, one K1+, and one Ti4+ atom.