DOI: 10.17188/1725228
title: Materials Data on Gd2MgS4 by Materials Project

description: MgGd2S4 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six S2- atoms to form MgS6 octahedra that share a cornercorner with one GdS6 octahedra, corners with two equivalent MgS6 octahedra, corners with four GdS7 pentagonal bipyramids, an edgeedge with one MgS6 octahedra, edges with four GdS6 octahedra, and edges with three GdS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 10–53°. There are a spread of Mg–S bond distances ranging from 2.55–2.93 Å. In the second Mg2+ site, Mg2+ is bonded to six S2- atoms to form MgS6 octahedra that share a cornercorner with one GdS6 octahedra, corners with two equivalent MgS6 octahedra, corners with four GdS7 pentagonal bipyramids, an edgeedge with one MgS6 octahedra, edges with four GdS6 octahedra, and edges with three GdS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 10–54°. There are a spread of Mg–S bond distances ranging from 2.55–2.82 Å. There are four inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded to six S2- atoms to form GdS6 octahedra that share a cornercorner with one MgS6 octahedra, corners with two equivalent GdS6 octahedra, corners with four GdS7 pentagonal bipyramids, an edgeedge with one GdS6 octahedra, edges with four MgS6 octahedra, and edges with three GdS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 11–54°. There are a spread of Gd–S bond distances ranging from 2.73–2.80 Å. In the second Gd3+ site, Gd3+ is bonded to six S2- atoms to form GdS6 octahedra that share a cornercorner with one MgS6 octahedra, corners with two equivalent GdS6 octahedra, corners with four GdS7 pentagonal bipyramids, an edgeedge with one GdS6 octahedra, edges with four MgS6 octahedra, and edges with three GdS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 11–53°. There are a spread of Gd–S bond distances ranging from 2.72–2.82 Å. In the third Gd3+ site, Gd3+ is bonded to seven S2- atoms to form distorted GdS7 pentagonal bipyramids that share corners with four MgS6 octahedra, corners with four GdS6 octahedra, edges with three MgS6 octahedra, edges with three GdS6 octahedra, and faces with two equivalent GdS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 15–71°. There are a spread of Gd–S bond distances ranging from 2.77–3.08 Å. In the fourth Gd3+ site, Gd3+ is bonded to seven S2- atoms to form distorted GdS7 pentagonal bipyramids that share corners with four MgS6 octahedra, corners with four GdS6 octahedra, edges with three MgS6 octahedra, edges with three GdS6 octahedra, and faces with two equivalent GdS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 17–70°. There are a spread of Gd–S bond distances ranging from 2.76–3.10 Å. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded to two Mg2+ and three Gd3+ atoms to form distorted SGd3Mg2 trigonal bipyramids that share corners with two equivalent SGd3Mg2 square pyramids, corners with three equivalent SGd3Mg tetrahedra, corners with two equivalent SGd3Mg2 trigonal bipyramids, edges with five SGd3Mg2 square pyramids, and edges with three SGd3Mg2 trigonal bipyramids. In the second S2- site, S2- is bonded to two Mg2+ and three Gd3+ atoms to form distorted SGd3Mg2 trigonal bipyramids that share corners with six SGd3Mg2 square pyramids, corners with two equivalent SGd3Mg tetrahedra, corners with two equivalent SGd3Mg2 trigonal bipyramids, edges with three SGd3Mg2 square pyramids, an edgeedge with one SGd3Mg tetrahedra, and edges with three SGd3Mg2 trigonal bipyramids. In the third S2- site, S2- is bonded to one Mg2+ and three Gd3+ atoms to form a mixture of distorted corner and edge-sharing SGd3Mg tetrahedra. In the fourth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Gd3+ atoms. In the fifth S2- site, S2- is bonded to two Mg2+ and three Gd3+ atoms to form distorted SGd3Mg2 square pyramids that share a cornercorner with one SGd3Mg tetrahedra, corners with eight SGd3Mg2 trigonal bipyramids, edges with four SGd3Mg2 square pyramids, an edgeedge with one SGd3Mg tetrahedra, and edges with two SGd3Mg2 trigonal bipyramids. In the sixth S2- site, S2- is bonded to two Mg2+ and three Gd3+ atoms to form distorted SGd3Mg2 square pyramids that share corners with two equivalent SGd4Mg square pyramids, a cornercorner with one SGd3Mg tetrahedra, corners with six SGd3Mg2 trigonal bipyramids, edges with three SGd3Mg2 square pyramids, an edgeedge with one SGd3Mg tetrahedra, and edges with three SGd3Mg2 trigonal bipyramids. In the seventh S2- site, S2- is bonded to one Mg2+ and four Gd3+ atoms to form distorted SGd4Mg square pyramids that share corners with two equivalent SGd3Mg2 square pyramids, corners with two equivalent SGd3Mg tetrahedra, corners with two equivalent SGd4Mg trigonal bipyramids, edges with three SGd3Mg2 square pyramids, an edgeedge with one SGd3Mg tetrahedra, and edges with five SGd3Mg2 trigonal bipyramids. In the eighth S2- site, S2- is bonded to one Mg2+ and four Gd3+ atoms to form distorted SGd4Mg trigonal bipyramids that share corners with eight SGd3Mg2 square pyramids, corners with three equivalent SGd3Mg tetrahedra, edges with two SGd3Mg2 square pyramids, and edges with four SGd3Mg2 trigonal bipyramids.