DOE OSTI2020
Pr3InSe6 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are three inequivalent Pr3+ sites. In the first Pr3+ site, Pr3+ is bonded to seven Se2- atoms to form distorted PrSe7 pentagonal bipyramids that share a cornercorner with one InSe6 octahedra, edges with two equivalent InSe6 octahedra, and edges with two equivalent PrSe7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are a spread of Pr–Se bond distances ranging from 2.98–3.14 Å. In the second Pr3+ site, Pr3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Pr–Se bond distances ranging from 3.03–3.33 Å. In the third Pr3+ site, Pr3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Pr–Se bond distances ranging from 3.02–3.14 Å. There are two inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share corners with two equivalent PrSe7 pentagonal bipyramids and edges with two equivalent InSe6 octahedra. There are two shorter (2.61 Å) and four longer (2.92 Å) In–Se bond lengths. In the second In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share edges with two equivalent InSe6 octahedra and edges with four equivalent PrSe7 pentagonal bipyramids. There are two shorter (2.78 Å) and four longer (2.80 Å) In–Se bond lengths. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three Pr3+ and two equivalent In3+ atoms to form distorted SePr3In2 trigonal bipyramids that share corners with two equivalent SePr4In square pyramids, corners with five SePr3In2 trigonal bipyramids, an edgeedge with one SePr4In square pyramid, and edges with three equivalent SePr3In2 trigonal bipyramids. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to five Pr3+ atoms. In the third Se2- site, Se2- is bonded to three Pr3+ and two equivalent In3+ atoms to form distorted SePr3In2 trigonal bipyramids that share corners with seven SePr3In2 trigonal bipyramids, edges with four equivalent SePr4In square pyramids, and an edgeedge with one SePr3In2 trigonal bipyramid. In the fourth Se2- site, Se2- is bonded to four Pr3+ and one In3+ atom to form distorted SePr4In square pyramids that share a cornercorner with one SePr4In square pyramid, corners with two equivalent SePr3In2 trigonal bipyramids, edges with two equivalent SePr4In square pyramids, and edges with five SePr3In2 trigonal bipyramids. In the fifth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Pr3+ and one In3+ atom. In the sixth Se2- site, Se2- is bonded in a 5-coordinate geometry to five Pr3+ atoms.