Materials Data on KAs2F7 by Materials Project
KAs2F7 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one KAs2F7 sheet oriented in the (0, 0, 1) direction. K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.70–3.17 Å. There are two inequivalent As3+ sites. In the first As3+ site, As3+ is bonded in a rectangular see-saw-like geometry to four F1- atoms. There are a spread of As–F bond distances ranging from 1.80–1.98 Å. In the second As3+ site, As3+ is bonded in a 3-coordinate geometry to three F1- atoms. There are a spread of As–F bond distances ranging from 1.78–1.80 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent K1+ and one As3+ atom. In the second F1- site, F1- is bonded in a 4-coordinate geometry to three equivalent K1+ and one As3+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one As3+ atom. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent K1+ and one As3+ atom. In the fifth F1- site, F1- is bonded in a 1-coordinate geometry to two equivalent K1+ and one As3+ atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one As3+ atom. In the seventh F1- site, F1- is bonded in a single-bond geometry to one K1+ and one As3+ atom.