DOE OSTI2020
Pr(LuS2)3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are three inequivalent Lu3+ sites. In the first Lu3+ site, Lu3+ is bonded to seven S2- atoms to form distorted LuS7 pentagonal bipyramids that share corners with three LuS6 octahedra, edges with two equivalent LuS6 octahedra, and edges with four equivalent LuS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–51°. There are a spread of Lu–S bond distances ranging from 2.65–2.88 Å. In the second Lu3+ site, Lu3+ is bonded to six S2- atoms to form LuS6 octahedra that share corners with three equivalent LuS6 octahedra, a cornercorner with one LuS7 pentagonal bipyramid, edges with four equivalent LuS6 octahedra, and edges with two equivalent LuS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Lu–S bond distances ranging from 2.64–2.74 Å. In the third Lu3+ site, Lu3+ is bonded to six S2- atoms to form LuS6 octahedra that share corners with three equivalent LuS6 octahedra, corners with two equivalent LuS7 pentagonal bipyramids, and edges with four equivalent LuS6 octahedra. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Lu–S bond distances ranging from 2.62–2.75 Å. Pr3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Pr–S bond distances ranging from 2.91–3.04 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to four Lu3+ atoms. In the second S2- site, S2- is bonded to three Lu3+ and one Pr3+ atom to form distorted SPrLu3 trigonal pyramids that share corners with two equivalent SPr2Lu3 square pyramids, corners with four SPr2Lu3 trigonal bipyramids, corners with two equivalent SPrLu3 trigonal pyramids, edges with three equivalent SPr2Lu3 square pyramids, and edges with two equivalent SPr3Lu2 trigonal bipyramids. In the third S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Lu3+ atoms. In the fourth S2- site, S2- is bonded to three equivalent Lu3+ and two equivalent Pr3+ atoms to form distorted SPr2Lu3 square pyramids that share corners with six SPr2Lu3 trigonal bipyramids, corners with two equivalent SPrLu3 trigonal pyramids, edges with four equivalent SPr2Lu3 square pyramids, edges with two SPr2Lu3 trigonal bipyramids, and edges with three equivalent SPrLu3 trigonal pyramids. In the fifth S2- site, S2- is bonded to three Lu3+ and two equivalent Pr3+ atoms to form distorted SPr2Lu3 trigonal bipyramids that share corners with two equivalent SPr2Lu3 square pyramids, corners with two equivalent SPr3Lu2 trigonal bipyramids, corners with three equivalent SPrLu3 trigonal pyramids, an edgeedge with one SPr2Lu3 square pyramid, and edges with five SPr2Lu3 trigonal bipyramids. In the sixth S2- site, S2- is bonded to two equivalent Lu3+ and three equivalent Pr3+ atoms to form distorted SPr3Lu2 trigonal bipyramids that share corners with four equivalent SPr2Lu3 square pyramids, corners with two equivalent SPr2Lu3 trigonal bipyramids, a cornercorner with one SPrLu3 trigonal pyramid, an edgeedge with one SPr2Lu3 square pyramid, edges with seven SPr2Lu3 trigonal bipyramids, and edges with two equivalent SPrLu3 trigonal pyramids.