Na3GdBr6 is Ilmenite-like structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to two equivalent Br(1), two equivalent Br(2), and two equivalent Br(3) atoms. In the second Na site, Na(2) is bonded to two equivalent Br(1), two equivalent Br(2), and two equivalent Br(3) atoms to form NaBr6 octahedra that share corners with six equivalent Gd(1)Br6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. Gd(1) is bonded to two equivalent Br(1), two equivalent Br(2), and two equivalent Br(3) atoms to form GdBr6 octahedra that share corners with six equivalent Na(2)Br6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. There are three inequivalent Br sites. In the first Br site, Br(1) is bonded in a 3-coordinate geometry to one Na(2), two equivalent Na(1), and one Gd(1) atom. In the second Br site, Br(2) is bonded to one Na(2), two equivalent Na(1), and one Gd(1) atom to form a mixture of distorted corner and edge-sharing BrNa3Gd trigonal pyramids. In the third Br site, Br(3) is bonded to one Na(2), two equivalent Na(1), and one Gd(1) atom to form a mixture of distorted corner and edge-sharing BrNa3Gd trigonal pyramids.
Na3GdBr6 is Ilmenite-like structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to two equivalent Br(1), two equivalent Br(2), and two equivalent Br(3) atoms. There is one shorter (2.96 Å) and one longer (3.47 Å) Na(1)-Br(1) bond length. There is one shorter (2.99 Å) and one longer (3.00 Å) Na(1)-Br(2) bond length. There is one shorter (3.04 Å) and one longer (3.26 Å) Na(1)-Br(3) bond length. In the second Na site, Na(2) is bonded to two equivalent Br(1), two equivalent Br(2), and two equivalent Br(3) atoms to form NaBr6 octahedra that share corners with six equivalent Gd(1)Br6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. Both Na(2)-Br(1) bond lengths are 2.86 Å. Both Na(2)-Br(2) bond lengths are 3.04 Å. Both Na(2)-Br(3) bond lengths are 2.92 Å. Gd(1) is bonded to two equivalent Br(1), two equivalent Br(2), and two equivalent Br(3) atoms to form GdBr6 octahedra that share corners with six equivalent Na(2)Br6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. Both Gd(1)-Br(1) bond lengths are 2.81 Å. Both Gd(1)-Br(2) bond lengths are 2.84 Å. Both Gd(1)-Br(3) bond lengths are 2.83 Å. There are three inequivalent Br sites. In the first Br site, Br(1) is bonded in a 3-coordinate geometry to one Na(2), two equivalent Na(1), and one Gd(1) atom. In the second Br site, Br(2) is bonded to one Na(2), two equivalent Na(1), and one Gd(1) atom to form a mixture of distorted corner and edge-sharing BrNa3Gd trigonal pyramids. In the third Br site, Br(3) is bonded to one Na(2), two equivalent Na(1), and one Gd(1) atom to form a mixture of distorted corner and edge-sharing BrNa3Gd trigonal pyramids.