Materials Data on Na3GdBr6 by Materials Project

Abstract

Na3GdBr6 is Ilmenite-like structured and crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six Br1- atoms to form NaBr6 octahedra that share corners with nine NaBr6 octahedra, edges with three equivalent GdBr6 octahedra, and a faceface with one NaBr6 octahedra. The corner-sharing octahedra tilt angles range from 50–62°. There are three shorter (2.98 Å) and three longer (3.10 Å) Na–Br bond lengths. In the second Na1+ site, Na1+ is bonded to six Br1- atoms to form NaBr6 octahedra that share corners with three equivalent NaBr6 octahedra, corners with six equivalent GdBr6 octahedra, edges with three equivalent NaBr6 octahedra, and a faceface with one NaBr6 octahedra. The corner-sharing octahedra tilt angles range from 41–62°. There are three shorter (2.97 Å) and three longer (3.06 Å) Na–Br bond lengths. In the third Na1+ site, Na1+ is bonded to six Br1- atoms to form distorted NaBr6 octahedra that share corners with three equivalent GdBr6 octahedra, corners with six equivalent NaBr6 octahedra, edges with three equivalent NaBr6 octahedra, and a faceface with one GdBr6 octahedra. The corner-sharing octahedra tilt angles range from 50–58°. There are three shorter (3.02 Å) and three longer (3.10 Å) Na–Br bond lengths. Gd3+ is bonded to six Br1- atoms to form GdBr6 octahedra that share corners with nine NaBr6 octahedra, edges with three equivalent NaBr6 octahedra, and a faceface with one NaBr6 octahedra. The corner-sharing octahedra tilt angles range from 41–58°. There are three shorter (2.84 Å) and three longer (2.86 Å) Gd–Br bond lengths. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted see-saw-like geometry to three Na1+ and one Gd3+ atom. In the second Br1- site, Br1- is bonded to three Na1+ and one Gd3+ atom to form a mixture of distorted corner and edge-sharing BrNa3Gd trigonal pyramids.