Materials Data on KAlFe2F2 by Materials Project
KFe2AlF2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. K is bonded in a rectangular see-saw-like geometry to four equivalent Fe atoms. All K–Fe bond lengths are 3.59 Å. Fe is bonded in a 2-coordinate geometry to two equivalent K, one Fe, and two equivalent Al atoms. The Fe–Fe bond length is 2.69 Å. Both Fe–Al bond lengths are 2.47 Å. Al is bonded in a linear geometry to four equivalent Fe and two equivalent F atoms. Both Al–F bond lengths are 1.85 Å. F is bonded in a single-bond geometry to one Al atom.