Materials Data on Yb4CrSe7 by Materials Project

Abstract

Yb4CrSe7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Yb+2.75+ sites. In the first Yb+2.75+ site, Yb+2.75+ is bonded to seven Se2- atoms to form distorted YbSe7 square pyramids that share corners with four YbSe6 octahedra, corners with four equivalent CrSe6 octahedra, corners with two equivalent YbSe7 pentagonal bipyramids, an edgeedge with one CrSe6 octahedra, edges with three equivalent YbSe6 octahedra, and faces with two equivalent YbSe7 square pyramids. The corner-sharing octahedra tilt angles range from 15–93°. There are a spread of Yb–Se bond distances ranging from 2.82–3.55 Å. In the second Yb+2.75+ site, Yb+2.75+ is bonded to seven Se2- atoms to form distorted YbSe7 pentagonal bipyramids that share corners with six YbSe6 octahedra, corners with two equivalent YbSe7 square pyramids, edges with two equivalent CrSe6 octahedra, edges with four YbSe6 octahedra, and faces with two equivalent YbSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 26–58°. There are a spread of Yb–Se bond distances ranging from 2.99–3.07 Å. In the third Yb+2.75+ site, Yb+2.75+ is bonded to six Se2- atoms to form YbSe6 octahedra that share a cornercorner with one YbSe6 octahedra, a cornercorner with one CrSe6 octahedra, corners with four equivalent YbSe7 pentagonal bipyramids, corners with two equivalent YbSe7 square pyramids, edges with two equivalent YbSe6 octahedra, an edgeedge with one YbSe7 pentagonal bipyramid, and edges with three equivalent YbSe7 square pyramids. The corner-sharing octahedra tilt angles range from 60–64°. There are a spread of Yb–Se bond distances ranging from 2.86–3.05 Å. In the fourth Yb+2.75+ site, Yb+2.75+ is bonded to six Se2- atoms to form distorted YbSe6 octahedra that share a cornercorner with one YbSe6 octahedra, corners with two equivalent CrSe6 octahedra, corners with two equivalent YbSe7 pentagonal bipyramids, corners with two equivalent YbSe7 square pyramids, edges with two equivalent YbSe6 octahedra, edges with three equivalent CrSe6 octahedra, and edges with three equivalent YbSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 19–64°. There are a spread of Yb–Se bond distances ranging from 2.86–3.24 Å. Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with three YbSe6 octahedra, corners with four equivalent YbSe7 square pyramids, edges with two equivalent CrSe6 octahedra, edges with three equivalent YbSe6 octahedra, edges with two equivalent YbSe7 pentagonal bipyramids, and an edgeedge with one YbSe7 square pyramid. The corner-sharing octahedra tilt angles range from 19–60°. There are a spread of Cr–Se bond distances ranging from 2.45–2.65 Å. There are seven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four Yb+2.75+ and one Cr3+ atom to form distorted SeYb4Cr trigonal bipyramids that share corners with two equivalent SeYb3Cr2 square pyramids, corners with four equivalent SeYb4 tetrahedra, corners with two equivalent SeYb5 trigonal bipyramids, edges with three equivalent SeYb3Cr2 square pyramids, an edgeedge with one SeYb4 tetrahedra, and edges with three SeYb4Cr trigonal bipyramids. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to three Yb+2.75+, two equivalent Cr3+, and one Se2- atom. The Se–Se bond length is 2.46 Å. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to four Yb+2.75+ and one Se2- atom. In the fourth Se2- site, Se2- is bonded to five Yb+2.75+ atoms to form distorted SeYb5 trigonal bipyramids that share corners with two equivalent SeYb3Cr2 square pyramids, corners with four equivalent SeYb4 tetrahedra, corners with two equivalent SeYb4Cr trigonal bipyramids, an edgeedge with one SeYb4 tetrahedra, and edges with three SeYb4Cr trigonal bipyramids. In the fifth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three Yb+2.75+ and one Cr3+ atom. In the sixth Se2- site, Se2- is bonded to four Yb+2.75+ atoms to form SeYb4 tetrahedra that share corners with two equivalent SeYb4 tetrahedra, corners with eight SeYb4Cr trigonal bipyramids, edges with two equivalent SeYb3Cr2 square pyramids, and edges with two SeYb4Cr trigonal bipyramids. In the seventh Se2- site, Se2- is bonded to three Yb+2.75+ and two equivalent Cr3+ atoms to form distorted SeYb3Cr2 square pyramids that share corners with four SeYb4Cr trigonal bipyramids, edges with two equivalent SeYb3Cr2 square pyramids, edges with two equivalent SeYb4 tetrahedra, and edges with three equivalent SeYb4Cr trigonal bipyramids.