Gd3Si2O8Br crystallizes in the orthorhombic Ima2 space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), and one Br(1) atom. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to two equivalent O(2), four equivalent O(1), and two equivalent Br(1) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one Si(1) atom. In the second O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one Si(1) atom. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Gd(1), two equivalent Gd(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Si(1) atom. Br(1) is bonded in a square co-planar geometry to two equivalent Gd(1) and two equivalent Gd(2) atoms.
Gd3Si2O8Br crystallizes in the orthorhombic Ima2 space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), and one Br(1) atom. The Gd(1)-O(1) bond length is 2.81 Å. There is one shorter (2.36 Å) and one longer (2.56 Å) Gd(1)-O(2) bond length. There is one shorter (2.29 Å) and one longer (2.39 Å) Gd(1)-O(3) bond length. There is one shorter (2.26 Å) and one longer (2.38 Å) Gd(1)-O(4) bond length. The Gd(1)-Br(1) bond length is 3.06 Å. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to two equivalent O(2), four equivalent O(1), and two equivalent Br(1) atoms. Both Gd(2)-O(2) bond lengths are 2.73 Å. There are two shorter (2.33 Å) and two longer (2.37 Å) Gd(2)-O(1) bond lengths. There is one shorter (2.96 Å) and one longer (3.00 Å) Gd(2)-Br(1) bond length. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Si(1)-O(1) bond length is 1.68 Å. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.63 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one Si(1) atom. In the second O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one Si(1) atom. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Gd(1), two equivalent Gd(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Si(1) atom. Br(1) is bonded in a square co-planar geometry to two equivalent Gd(1) and two equivalent Gd(2) atoms.