DOE OSTI2020
Ta12MoO33 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are six inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form distorted TaO6 octahedra that share corners with four TaO6 octahedra, a cornercorner with one MoO4 tetrahedra, and edges with two equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 5–31°. There are a spread of Ta–O bond distances ranging from 1.85–2.25 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form distorted TaO6 octahedra that share corners with four TaO6 octahedra, a cornercorner with one MoO4 tetrahedra, and edges with two equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 6–30°. There are a spread of Ta–O bond distances ranging from 1.85–2.27 Å. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are a spread of Ta–O bond distances ranging from 1.92–2.11 Å. In the fourth Ta5+ site, Ta5+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 6–32°. There are a spread of Ta–O bond distances ranging from 1.84–2.31 Å. In the fifth Ta5+ site, Ta5+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 3–33°. There are a spread of Ta–O bond distances ranging from 1.81–2.34 Å. In the sixth Ta5+ site, Ta5+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 3–31°. There are a spread of Ta–O bond distances ranging from 1.85–2.28 Å. Mo6+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with four TaO6 octahedra. The corner-sharing octahedral tilt angles are 45°. There is two shorter (1.79 Å) and two longer (1.80 Å) Mo–O bond length. There are seventeen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two Ta5+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two Ta5+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to two Ta5+ atoms. In the sixth O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Ta5+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ta5+ and one Mo6+ atom. In the ninth O2- site, O2- is bonded in a linear geometry to two Ta5+ atoms. In the tenth O2- site, O2- is bonded in a linear geometry to two Ta5+ atoms. In the eleventh O2- site, O2- is bonded in a linear geometry to two Ta5+ atoms. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ta5+ and one Mo6+ atom. In the fourteenth O2- site, O2- is bonded in a linear geometry to two Ta5+ atoms. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ atoms. In the sixteenth O2- site, O2- is bonded in a linear geometry to two Ta5+ atoms. In the seventeenth O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms.