Materials Data on KFe2(MoO5)2 by Materials Project
KFe2(MoO5)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K is bonded to six O atoms to form distorted KO6 octahedra that share corners with four equivalent FeO6 octahedra and corners with six equivalent MoO4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are four shorter (2.72 Å) and two longer (3.01 Å) K–O bond lengths. Mo is bonded to four O atoms to form MoO4 tetrahedra that share corners with three equivalent KO6 octahedra and corners with four equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 45–72°. There are a spread of Mo–O bond distances ranging from 1.74–1.88 Å. Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent KO6 octahedra, corners with four equivalent MoO4 tetrahedra, and edges with two equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 61°. There are a spread of Fe–O bond distances ranging from 1.86–2.15 Å. There are four inequivalent O sites. In the first O site, O is bonded in a water-like geometry to two equivalent Fe atoms. In the second O site, O is bonded in a trigonal planar geometry to one K, one Mo, and one Fe atom. In the third O site, O is bonded in a distorted single-bond geometry to one K and one Mo atom. In the fourth O site, O is bonded in a distorted T-shaped geometry to one Mo and two equivalent Fe atoms.