Materials Data on KSbAs(O2F)2 by Materials Project
KSbAs(O2F)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. 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 2.70–3.25 Å. There are a spread of K–F bond distances ranging from 2.59–3.05 Å. Sb is bonded to three O and two F atoms to form SbO3F2 square pyramids that share corners with three equivalent AsO4 tetrahedra. There are a spread of Sb–O bond distances ranging from 2.05–2.08 Å. There is one shorter (1.96 Å) and one longer (2.01 Å) Sb–F bond length. As is bonded to four O atoms to form AsO4 tetrahedra that share corners with three equivalent SbO3F2 square pyramids. There are a spread of As–O bond distances ranging from 1.67–1.77 Å. There are four inequivalent O sites. In the first O site, O is bonded in a distorted bent 120 degrees geometry to one K, one Sb, and one As atom. In the second O site, O is bonded in a 1-coordinate geometry to one K and one As atom. In the third O site, O is bonded in a 2-coordinate geometry to one K, one Sb, and one As atom. In the fourth O site, O is bonded in a 2-coordinate geometry to one K, one Sb, and one As atom. There are two inequivalent F sites. In the first F site, F is bonded in a 3-coordinate geometry to two equivalent K and one Sb atom. In the second F site, F is bonded in a 2-coordinate geometry to two equivalent K and one Sb atom.