DOI: 10.17188/1740493
title: Materials Data on Pr9Al5S21 by Materials Project

description: Pr9Al5S21 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are six inequivalent Pr3+ sites. In the first Pr3+ site, Pr3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Pr–S bond distances ranging from 2.86–3.05 Å. In the second Pr3+ site, Pr3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Pr–S bond distances ranging from 2.85–3.27 Å. In the third Pr3+ site, Pr3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Pr–S bond distances ranging from 2.86–3.13 Å. In the fourth Pr3+ site, Pr3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Pr–S bond distances ranging from 2.84–3.05 Å. In the fifth Pr3+ site, Pr3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Pr–S bond distances ranging from 2.84–3.27 Å. In the sixth Pr3+ site, Pr3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Pr–S bond distances ranging from 2.88–3.13 Å. There are six inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Al–S bond distances ranging from 2.22–2.26 Å. In the second Al3+ site, Al3+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Al–S bond distances ranging from 2.22–2.26 Å. In the third Al3+ site, Al3+ is bonded to six S2- atoms to form face-sharing AlS6 octahedra. There are three shorter (2.43 Å) and three longer (2.51 Å) Al–S bond lengths. In the fourth Al3+ site, Al3+ is bonded to six S2- atoms to form face-sharing AlS6 octahedra. There are three shorter (2.35 Å) and three longer (2.63 Å) Al–S bond lengths. In the fifth Al3+ site, Al3+ is bonded to six S2- atoms to form face-sharing AlS6 octahedra. There are three shorter (2.35 Å) and three longer (2.63 Å) Al–S bond lengths. In the sixth Al3+ site, Al3+ is bonded to six S2- atoms to form face-sharing AlS6 octahedra. There are three shorter (2.43 Å) and three longer (2.51 Å) Al–S bond lengths. There are fourteen inequivalent S2- sites. In the first S2- site, S2- is bonded to three Pr3+ and one Al3+ atom to form distorted SPr3Al tetrahedra that share corners with three SPr3Al2 square pyramids and corners with two equivalent SPr3Al trigonal pyramids. In the second S2- site, S2- is bonded to three Pr3+ and one Al3+ atom to form distorted SPr3Al tetrahedra that share corners with three SPr3Al2 square pyramids and a cornercorner with one SPr3Al trigonal pyramid. In the third S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Pr3+ and one Al3+ atom. In the fourth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Pr3+ and one Al3+ atom. In the fifth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Pr3+ and one Al3+ atom. In the sixth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Pr3+ and one Al3+ atom. In the seventh S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Pr3+ and one Al3+ atom. In the eighth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Pr3+ and one Al3+ atom. In the ninth S2- site, S2- is bonded in a 5-coordinate geometry to four Pr3+ and one Al3+ atom. In the tenth S2- site, S2- is bonded to three Pr3+ and two Al3+ atoms to form distorted SPr3Al2 square pyramids that share corners with three SPr3Al tetrahedra, a cornercorner with one SPr3Al trigonal pyramid, edges with two equivalent SPr3Al trigonal pyramids, and faces with two equivalent SPr3Al2 square pyramids. In the eleventh S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Pr3+ and one Al3+ atom. In the twelfth S2- site, S2- is bonded to three Pr3+ and two Al3+ atoms to form distorted SPr3Al2 square pyramids that share corners with three SPr3Al tetrahedra and faces with two equivalent SPr3Al2 square pyramids. In the thirteenth S2- site, S2- is bonded to three Pr3+ and one Al3+ atom to form distorted SPr3Al trigonal pyramids that share a cornercorner with one SPr3Al2 square pyramid, corners with three SPr3Al tetrahedra, edges with two equivalent SPr3Al2 square pyramids, and edges with two equivalent SPr3Al trigonal pyramids. In the fourteenth S2- site, S2- is bonded in a 5-coordinate geometry to four Pr3+ and one Al3+ atom.