DOE OSTI2020
Pr6N3S4Br crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are six inequivalent Pr3+ sites. In the first Pr3+ site, Pr3+ is bonded in a 2-coordinate geometry to two N3-, four S2-, and one Br1- atom. There are one shorter (2.39 Å) and one longer (2.47 Å) Pr–N bond lengths. There are two shorter (2.83 Å) and two longer (3.05 Å) Pr–S bond lengths. The Pr–Br bond length is 3.53 Å. In the second Pr3+ site, Pr3+ is bonded in a 1-coordinate geometry to one N3-, four S2-, and one Br1- atom. The Pr–N bond length is 2.23 Å. There are two shorter (2.88 Å) and two longer (2.96 Å) Pr–S bond lengths. The Pr–Br bond length is 3.17 Å. In the third Pr3+ site, Pr3+ is bonded in a 2-coordinate geometry to two equivalent N3-, three S2-, and two equivalent Br1- atoms. Both Pr–N bond lengths are 2.40 Å. There are one shorter (3.06 Å) and two longer (3.07 Å) Pr–S bond lengths. Both Pr–Br bond lengths are 3.15 Å. In the fourth Pr3+ site, Pr3+ is bonded in a 7-coordinate geometry to three equivalent N3-, three S2-, and one Br1- atom. There are one shorter (2.37 Å) and two longer (2.45 Å) Pr–N bond lengths. There are two shorter (3.02 Å) and one longer (3.19 Å) Pr–S bond lengths. The Pr–Br bond length is 3.24 Å. In the fifth Pr3+ site, Pr3+ is bonded in a 2-coordinate geometry to two equivalent N3- and five S2- atoms. Both Pr–N bond lengths are 2.42 Å. There are a spread of Pr–S bond distances ranging from 2.81–3.33 Å. In the sixth Pr3+ site, Pr3+ is bonded in a 6-coordinate geometry to two N3- and four S2- atoms. There are one shorter (2.35 Å) and one longer (2.38 Å) Pr–N bond lengths. There are two shorter (2.95 Å) and two longer (2.96 Å) Pr–S bond lengths. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded to four Pr3+ atoms to form NPr4 tetrahedra that share corners with eight SPr6 octahedra, corners with two equivalent NPr4 tetrahedra, an edgeedge with one SPr6 octahedra, an edgeedge with one NPr4 tetrahedra, and edges with two equivalent SPr5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 25–69°. In the second N3- site, N3- is bonded to four Pr3+ atoms to form NPr4 tetrahedra that share corners with two equivalent NPr4 tetrahedra, corners with two equivalent SPr5 trigonal bipyramids, edges with four equivalent SPr6 octahedra, and an edgeedge with one NPr4 tetrahedra. In the third N3- site, N3- is bonded to four Pr3+ atoms to form NPr4 tetrahedra that share a cornercorner with one SPr6 octahedra, corners with two equivalent NPr4 tetrahedra, corners with four equivalent SPr5 trigonal bipyramids, edges with two equivalent SPr6 octahedra, edges with two equivalent NPr4 tetrahedra, and an edgeedge with one SPr5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 36°. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to six Pr3+ atoms to form distorted SPr6 octahedra that share corners with two equivalent SPr6 octahedra, corners with four equivalent NPr4 tetrahedra, corners with two equivalent SPr5 trigonal bipyramids, edges with two equivalent SPr6 octahedra, edges with four equivalent NPr4 tetrahedra, and an edgeedge with one SPr5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 35°. In the second S2- site, S2- is bonded in a 6-coordinate geometry to six Pr3+ atoms. In the third S2- site, S2- is bonded to five Pr3+ atoms to form distorted SPr5 trigonal bipyramids that share corners with three SPr6 octahedra, corners with six NPr4 tetrahedra, edges with three SPr6 octahedra, edges with three NPr4 tetrahedra, and edges with two equivalent SPr5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 26–39°. In the fourth S2- site, S2- is bonded to six Pr3+ atoms to form distorted SPr6 octahedra that share corners with five NPr4 tetrahedra, a cornercorner with one SPr5 trigonal bipyramid, edges with four equivalent SPr6 octahedra, edges with three NPr4 tetrahedra, and edges with two equivalent SPr5 trigonal bipyramids. Br1- is bonded in a 5-coordinate geometry to five Pr3+ atoms.