Materials Data on K2Mo8O13 by Materials Project
K2Mo8O13 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight O2- atoms. All K–O bond lengths are 3.15 Å. There are four inequivalent Mo3+ sites. In the first Mo3+ site, Mo3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MoO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mo–O bond distances ranging from 2.06–2.30 Å. In the second Mo3+ site, Mo3+ is bonded to five O2- atoms to form MoO5 square pyramids that share corners with two equivalent MoO6 octahedra and edges with two equivalent MoO5 square pyramids. The corner-sharing octahedral tilt angles are 53°. There are one shorter (2.06 Å) and four longer (2.16 Å) Mo–O bond lengths. In the third Mo3+ site, Mo3+ is bonded in a see-saw-like geometry to four O2- atoms. There are two shorter (2.05 Å) and two longer (2.10 Å) Mo–O bond lengths. In the fourth Mo3+ site, Mo3+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with two equivalent MoO6 octahedra, corners with two equivalent MoO5 square pyramids, and edges with seven MoO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mo–O bond distances ranging from 2.06–2.37 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to six Mo3+ atoms to form edge-sharing OMo6 octahedra. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Mo3+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to three Mo3+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent K1+ and three Mo3+ atoms. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent K1+ and three Mo3+ atoms.