DOE OSTI2020
YbPr11Se16 crystallizes in the orthorhombic P2_12_12 space group. The structure is three-dimensional. Yb is bonded to eight Se atoms to form distorted YbSe8 hexagonal bipyramids that share corners with eight PrSe8 hexagonal bipyramids, edges with four PrSe8 hexagonal bipyramids, and faces with eight PrSe8 hexagonal bipyramids. There are a spread of Yb–Se bond distances ranging from 3.01–3.21 Å. There are six inequivalent Pr sites. In the first Pr site, Pr is bonded to eight Se atoms to form distorted PrSe8 hexagonal bipyramids that share a cornercorner with one YbSe8 hexagonal bipyramid, corners with seven PrSe8 hexagonal bipyramids, edges with four PrSe8 hexagonal bipyramids, a faceface with one YbSe8 hexagonal bipyramid, and faces with seven PrSe8 hexagonal bipyramids. There are a spread of Pr–Se bond distances ranging from 3.02–3.21 Å. In the second Pr site, Pr is bonded to eight Se atoms to form distorted PrSe8 hexagonal bipyramids that share a cornercorner with one YbSe8 hexagonal bipyramid, corners with seven PrSe8 hexagonal bipyramids, edges with four PrSe8 hexagonal bipyramids, a faceface with one YbSe8 hexagonal bipyramid, and faces with seven PrSe8 hexagonal bipyramids. There are a spread of Pr–Se bond distances ranging from 3.01–3.22 Å. In the third Pr site, Pr is bonded to eight Se atoms to form distorted PrSe8 hexagonal bipyramids that share a cornercorner with one YbSe8 hexagonal bipyramid, corners with seven PrSe8 hexagonal bipyramids, edges with four PrSe8 hexagonal bipyramids, a faceface with one YbSe8 hexagonal bipyramid, and faces with seven PrSe8 hexagonal bipyramids. There are a spread of Pr–Se bond distances ranging from 3.04–3.21 Å. In the fourth Pr site, Pr is bonded to eight Se atoms to form distorted PrSe8 hexagonal bipyramids that share corners with eight PrSe8 hexagonal bipyramids, an edgeedge with one YbSe8 hexagonal bipyramid, edges with three PrSe8 hexagonal bipyramids, and faces with eight PrSe8 hexagonal bipyramids. There are a spread of Pr–Se bond distances ranging from 3.02–3.22 Å. In the fifth Pr site, Pr is bonded to eight Se atoms to form distorted PrSe8 hexagonal bipyramids that share a cornercorner with one YbSe8 hexagonal bipyramid, corners with seven PrSe8 hexagonal bipyramids, edges with four PrSe8 hexagonal bipyramids, a faceface with one YbSe8 hexagonal bipyramid, and faces with seven PrSe8 hexagonal bipyramids. There are a spread of Pr–Se bond distances ranging from 3.03–3.21 Å. In the sixth Pr site, Pr is bonded to eight Se atoms to form distorted PrSe8 hexagonal bipyramids that share corners with eight PrSe8 hexagonal bipyramids, edges with two equivalent YbSe8 hexagonal bipyramids, edges with two equivalent PrSe8 hexagonal bipyramids, and faces with eight PrSe8 hexagonal bipyramids. There are a spread of Pr–Se bond distances ranging from 3.02–3.21 Å. There are eight inequivalent Se sites. In the first Se site, Se is bonded to one Yb and five Pr atoms to form a mixture of distorted edge, face, and corner-sharing SeYbPr5 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the second Se site, Se is bonded to six Pr atoms to form distorted SePr6 octahedra that share corners with fifteen SeYbPr5 octahedra, edges with six SeYbPr5 octahedra, and faces with five SePr6 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the third Se site, Se is bonded to one Yb and five Pr atoms to form a mixture of distorted edge, face, and corner-sharing SeYbPr5 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the fourth Se site, Se is bonded to one Yb and five Pr atoms to form distorted SeYbPr5 octahedra that share corners with fifteen SeYbPr5 octahedra, edges with six SeYbPr5 octahedra, and faces with five SePr6 octahedra. The corner-sharing octahedra tilt angles range from 17–50°. In the fifth Se site, Se is bonded to six Pr atoms to form a mixture of distorted edge, face, and corner-sharing SePr6 octahedra. The corner-sharing octahedra tilt angles range from 16–50°. In the sixth Se site, Se is bonded to six Pr atoms to form a mixture of distorted edge, face, and corner-sharing SePr6 octahedra. The corner-sharing octahedra tilt angles range from 16–50°. In the seventh Se site, Se is bonded to six Pr atoms to form a mixture of distorted edge, face, and corner-sharing SePr6 octahedra. The corner-sharing octahedra tilt angles range from 16–50°. In the eighth Se site, Se is bonded to one Yb and five Pr atoms to form distorted SeYbPr5 octahedra that share corners with fifteen SeYbPr5 octahedra, edges with six SePr6 octahedra, and faces with five SeYbPr5 octahedra. The corner-sharing octahedra tilt angles range from 17–50°.