Materials Data on K2W2O5 by Materials Project
K2W2O5 crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.62–3.10 Å. There are two inequivalent W4+ sites. In the first W4+ site, W4+ is bonded to six O2- atoms to form WO6 octahedra that share corners with four equivalent WO6 octahedra and corners with two equivalent WO4 tetrahedra. The corner-sharing octahedral tilt angles are 8°. There are a spread of W–O bond distances ranging from 2.09–2.21 Å. In the second W4+ site, W4+ is bonded to four O2- atoms to form WO4 tetrahedra that share corners with two equivalent WO6 octahedra and corners with two equivalent WO4 tetrahedra. The corner-sharing octahedral tilt angles are 28°. There are a spread of W–O bond distances ranging from 1.92–2.04 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent K1+ and two equivalent W4+ atoms to form distorted OK4W2 octahedra that share corners with two equivalent OK4W2 octahedra, corners with four equivalent OK2W2 tetrahedra, edges with two equivalent OK4W2 octahedra, and faces with four equivalent OK4W2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent K1+ and two W4+ atoms. In the third O2- site, O2- is bonded to two equivalent K1+ and two equivalent W4+ atoms to form distorted OK2W2 tetrahedra that share corners with eight equivalent OK4W2 octahedra and corners with two equivalent OK2W2 tetrahedra. The corner-sharing octahedra tilt angles range from 19–83°.