Materials Data on K2P2O5F2 by Materials Project
K2P2O5F2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K1+ is bonded in a 7-coordinate geometry to six O2- and two equivalent F1- atoms. There are a spread of K–O bond distances ranging from 2.75–3.06 Å. There are one shorter (3.03 Å) and one longer (3.36 Å) K–F bond lengths. P5+ is bonded to three O2- and one F1- atom to form corner-sharing PO3F tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.63 Å. The P–F bond length is 1.60 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent K1+ and one P5+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent P5+ atoms. In the third O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent K1+ and one P5+ atom. F1- is bonded in a single-bond geometry to two equivalent K1+ and one P5+ atom.