Er3Sb5O12 crystallizes in the cubic I-43m space group. Er(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 3-coordinate geometry to three equivalent O(1) atoms. In the second Sb site, Sb(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Er(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Er(1) and one Sb(2) atom.
Er3Sb5O12 crystallizes in the cubic I-43m space group. Er(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. All Er(1)-O(1) bond lengths are 2.55 Å. All Er(1)-O(2) bond lengths are 2.21 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 3-coordinate geometry to three equivalent O(1) atoms. All Sb(1)-O(1) bond lengths are 2.01 Å. In the second Sb site, Sb(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Sb(2)-O(1) bond lengths are 2.19 Å. Both Sb(2)-O(2) bond lengths are 1.97 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Er(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Er(1) and one Sb(2) atom.