Er5Co2Te2 crystallizes in the orthorhombic Cmcm space group. There are three inequivalent Er sites. In the first Er site, Er(1) is bonded in a distorted square co-planar geometry to one Co(1), one Co(2), and two equivalent Te(1) atoms. In the second Er site, Er(2) is bonded in a 6-coordinate geometry to one Co(1), two equivalent Co(2), and three equivalent Te(1) atoms. In the third Er site, Er(3) is bonded in a 7-coordinate geometry to one Co(2), two equivalent Co(1), and four equivalent Te(1) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Er(1), two equivalent Er(2), four equivalent Er(3), and two equivalent Co(2) atoms. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Er(1), two equivalent Er(3), four equivalent Er(2), and two equivalent Co(1) atoms. Te(1) is bonded in a 8-coordinate geometry to one Er(1), three equivalent Er(2), and four equivalent Er(3) atoms.
Er5Co2Te2 crystallizes in the orthorhombic Cmcm space group. There are three inequivalent Er sites. In the first Er site, Er(1) is bonded in a distorted square co-planar geometry to one Co(1), one Co(2), and two equivalent Te(1) atoms. The Er(1)-Co(1) bond length is 2.88 Å. The Er(1)-Co(2) bond length is 3.28 Å. Both Er(1)-Te(1) bond lengths are 3.16 Å. In the second Er site, Er(2) is bonded in a 6-coordinate geometry to one Co(1), two equivalent Co(2), and three equivalent Te(1) atoms. The Er(2)-Co(1) bond length is 2.92 Å. Both Er(2)-Co(2) bond lengths are 2.80 Å. There is one shorter (3.13 Å) and two longer (3.18 Å) Er(2)-Te(1) bond lengths. In the third Er site, Er(3) is bonded in a 7-coordinate geometry to one Co(2), two equivalent Co(1), and four equivalent Te(1) atoms. The Er(3)-Co(2) bond length is 2.78 Å. Both Er(3)-Co(1) bond lengths are 2.78 Å. There are two shorter (3.32 Å) and two longer (3.34 Å) Er(3)-Te(1) bond lengths. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Er(1), two equivalent Er(2), four equivalent Er(3), and two equivalent Co(2) atoms. Both Co(1)-Co(2) bond lengths are 2.37 Å. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Er(1), two equivalent Er(3), four equivalent Er(2), and two equivalent Co(1) atoms. Te(1) is bonded in a 8-coordinate geometry to one Er(1), three equivalent Er(2), and four equivalent Er(3) atoms.