DOE OSTI2020
Dy5(ReO6)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are five inequivalent Dy3+ sites. In the first Dy3+ site, Dy3+ is bonded to seven O2- atoms to form distorted DyO7 pentagonal bipyramids that share corners with two equivalent DyO6 octahedra, an edgeedge with one DyO6 octahedra, edges with two equivalent ReO6 octahedra, and edges with two equivalent DyO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 56°. There are a spread of Dy–O bond distances ranging from 2.28–2.42 Å. In the second Dy3+ site, Dy3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Dy–O bond distances ranging from 2.28–2.50 Å. In the third Dy3+ site, Dy3+ is bonded to six O2- atoms to form DyO6 octahedra that share corners with four equivalent ReO6 octahedra, corners with four DyO7 pentagonal bipyramids, and edges with two DyO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 38°. There are two shorter (2.22 Å) and four longer (2.32 Å) Dy–O bond lengths. In the fourth Dy3+ site, Dy3+ is bonded to seven O2- atoms to form distorted DyO7 pentagonal bipyramids that share corners with two equivalent DyO6 octahedra, an edgeedge with one DyO6 octahedra, edges with two equivalent ReO6 octahedra, and edges with two equivalent DyO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 57°. There are a spread of Dy–O bond distances ranging from 2.28–2.43 Å. In the fifth Dy3+ site, Dy3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Dy–O bond distances ranging from 2.28–2.49 Å. Re+4.50+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with two equivalent DyO6 octahedra, edges with two equivalent ReO6 octahedra, and edges with two DyO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 38°. There are a spread of Re–O bond distances ranging from 1.97–2.10 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to three Dy3+ and one Re+4.50+ atom to form distorted ODy3Re tetrahedra that share corners with ten ODy3Re tetrahedra, a cornercorner with one ODy2Re2 trigonal pyramid, edges with four ODy3Re tetrahedra, and an edgeedge with one ODy2Re2 trigonal pyramid. In the second O2- site, O2- is bonded to four Dy3+ atoms to form ODy4 tetrahedra that share corners with twelve ODy3Re tetrahedra, a cornercorner with one ODy2Re2 trigonal pyramid, and edges with four ODy4 tetrahedra. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Dy3+ and two equivalent Re+4.50+ atoms. In the fourth O2- site, O2- is bonded to two Dy3+ and two equivalent Re+4.50+ atoms to form distorted ODy2Re2 tetrahedra that share corners with eight ODy4 tetrahedra, edges with four ODy3Re tetrahedra, and an edgeedge with one ODy2Re2 trigonal pyramid. In the fifth O2- site, O2- is bonded to two Dy3+ and two equivalent Re+4.50+ atoms to form distorted ODy2Re2 trigonal pyramids that share corners with eight ODy3Re tetrahedra and edges with five ODy2Re2 tetrahedra. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Dy3+ and two equivalent Re+4.50+ atoms. In the seventh O2- site, O2- is bonded to three Dy3+ and one Re+4.50+ atom to form distorted ODy3Re tetrahedra that share corners with eleven ODy3Re tetrahedra, edges with four ODy3Re tetrahedra, and an edgeedge with one ODy2Re2 trigonal pyramid. In the eighth O2- site, O2- is bonded to four Dy3+ atoms to form ODy4 tetrahedra that share corners with eleven ODy3Re tetrahedra, corners with two equivalent ODy2Re2 trigonal pyramids, and edges with four ODy4 tetrahedra.