Materials Data on Ce2MgS4 by Materials Project

MgCe2S4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mg2+ is bonded to five S2- atoms to form MgS5 square pyramids that share corners with four CeS6 octahedra, edges with four CeS6 octahedra, and edges with four equivalent MgS5 square pyramids. The corner-sharing octahedral tilt angles are 6°. There are one shorter (2.51 Å) and four longer (2.65 Å) Mg–S bond lengths. There are two inequivalent Ce3+ sites. In the first Ce3+ site, Ce3+ is bonded to six S2- atoms to form CeS6 octahedra that share corners with three equivalent CeS6 octahedra, corners with two equivalent MgS5 square pyramids, edges with six CeS6 octahedra, and an edgeedge with one MgS5 square pyramid. The corner-sharing octahedra tilt angles range from 55–60°. There are a spread of Ce–S bond distances ranging from 2.77–2.89 Å. In the second Ce3+ site, Ce3+ is bonded to six S2- atoms to form CeS6 octahedra that share corners with three equivalent CeS6 octahedra, corners with two equivalent MgS5 square pyramids, edges with four CeS6 octahedra, and edges with three equivalent MgS5 square pyramids. The corner-sharing octahedra tilt angles range from 55–60°. There are a spread of Ce–S bond distances ranging from 2.74–2.94 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Mg2+ and two equivalent Ce3+ atoms to form a mixture of edge and corner-sharing SCe2Mg3 square pyramids. In the second S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Ce3+ atoms. In the third S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to three Ce3+ atoms. In the fourth S2- site, S2- is bonded to two equivalent Mg2+ and three Ce3+ atoms to form SCe3Mg2 square pyramids that share corners with two equivalent SCe2Mg3 square pyramids and edges with five SCe3Mg2 square pyramids.