DOE OSTI2020
La5Mo6O21 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are five inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.46–2.71 Å. In the second La3+ site, La3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of La–O bond distances ranging from 2.48–2.93 Å. In the third La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.40–2.88 Å. In the fourth La3+ site, La3+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of La–O bond distances ranging from 2.44–2.98 Å. In the fifth La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.44–2.86 Å. There are six inequivalent Mo+4.50+ sites. In the first Mo+4.50+ site, Mo+4.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MoO6 octahedra. The corner-sharing octahedra tilt angles range from 43–52°. There are a spread of Mo–O bond distances ranging from 1.98–2.15 Å. In the second Mo+4.50+ site, Mo+4.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MoO6 octahedra. The corner-sharing octahedral tilt angles are 15°. There are a spread of Mo–O bond distances ranging from 1.97–2.17 Å. In the third Mo+4.50+ site, Mo+4.50+ is bonded to six O2- atoms to form corner-sharing MoO6 octahedra. The corner-sharing octahedra tilt angles range from 15–59°. There are a spread of Mo–O bond distances ranging from 1.85–2.22 Å. In the fourth Mo+4.50+ site, Mo+4.50+ is bonded to six O2- atoms to form corner-sharing MoO6 octahedra. The corner-sharing octahedra tilt angles range from 16–50°. There are a spread of Mo–O bond distances ranging from 1.91–2.17 Å. In the fifth Mo+4.50+ site, Mo+4.50+ is bonded to six O2- atoms to form corner-sharing MoO6 octahedra. The corner-sharing octahedra tilt angles range from 16–37°. There are a spread of Mo–O bond distances ranging from 1.83–2.17 Å. In the sixth Mo+4.50+ site, Mo+4.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MoO6 octahedra. The corner-sharing octahedra tilt angles range from 50–59°. There are a spread of Mo–O bond distances ranging from 2.01–2.17 Å. There are twenty-one inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three La3+ and one Mo+4.50+ atom. In the second O2- site, O2- is bonded in a distorted L-shaped geometry to two La3+ and two Mo+4.50+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three La3+ and one Mo+4.50+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two La3+ and two Mo+4.50+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two La3+ and one Mo+4.50+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two La3+ and one Mo+4.50+ atom. In the seventh O2- site, O2- is bonded to two La3+ and two Mo+4.50+ atoms to form distorted OLa2Mo2 trigonal pyramids that share a cornercorner with one OLa3Mo tetrahedra, a cornercorner with one OLa2Mo2 trigonal pyramid, and an edgeedge with one OLa2Mo2 trigonal pyramid. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one La3+ and three Mo+4.50+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two La3+ and two Mo+4.50+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two La3+ and two Mo+4.50+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one La3+ and two Mo+4.50+ atoms. In the twelfth O2- site, O2- is bonded to two La3+ and two Mo+4.50+ atoms to form distorted OLa2Mo2 trigonal pyramids that share a cornercorner with one OLa3Mo tetrahedra, a cornercorner with one OLa2Mo2 trigonal pyramid, and an edgeedge with one OLa2Mo2 trigonal pyramid. In the thirteenth O2- site, O2- is bonded in a 2-coordinate geometry to two La3+ and two Mo+4.50+ atoms. In the fourteenth O2- site, O2- is bonded to three La3+ and one Mo+4.50+ atom to form distorted corner-sharing OLa3Mo tetrahedra. In the fifteenth O2- site, O2- is bonded in a distorted T-shaped geometry to three Mo+4.50+ atoms. In the sixteenth O2- site, O2- is bonded in a 4-coordinate geometry to two La3+ and two Mo+4.50+ atoms. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Mo+4.50+ atom. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to two La3+ and two Mo+4.50+ atoms. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one La3+ and two equivalent Mo+4.50+ atoms. In the twentieth O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Mo+4.50+ atom. In the twenty-first O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Mo+4.50+ atom.