Er6Co2Sn crystallizes in the orthorhombic Immm space group. There are three inequivalent Er sites. In the first Er site, Er(1) is bonded in a 4-coordinate geometry to one Co(1), two equivalent Co(2), and one Sn(1) atom. In the second Er site, Er(2) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Co(2), one Sn(1), and one Sn(2) atom. In the third Er site, Er(3) is bonded in a 5-coordinate geometry to one Co(2), two equivalent Co(1), one Sn(1), and one Sn(2) atom. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to two equivalent Er(1), two equivalent Er(2), four equivalent Er(3), and one Co(1) atom. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to two equivalent Er(2), two equivalent Er(3), four equivalent Er(1), and one Co(2) atom. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a cuboctahedral geometry to four equivalent Er(1), four equivalent Er(2), and four equivalent Er(3) atoms. In the second Sn site, Sn(2) is bonded in a body-centered cubic geometry to four equivalent Er(2) and four equivalent Er(3) atoms.
Er6Co2Sn crystallizes in the orthorhombic Immm space group. There are three inequivalent Er sites. In the first Er site, Er(1) is bonded in a 4-coordinate geometry to one Co(1), two equivalent Co(2), and one Sn(1) atom. The Er(1)-Co(1) bond length is 2.72 Å. Both Er(1)-Co(2) bond lengths are 2.82 Å. The Er(1)-Sn(1) bond length is 3.38 Å. In the second Er site, Er(2) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Co(2), one Sn(1), and one Sn(2) atom. The Er(2)-Co(1) bond length is 3.12 Å. The Er(2)-Co(2) bond length is 2.76 Å. The Er(2)-Sn(1) bond length is 3.33 Å. The Er(2)-Sn(2) bond length is 3.04 Å. In the third Er site, Er(3) is bonded in a 5-coordinate geometry to one Co(2), two equivalent Co(1), one Sn(1), and one Sn(2) atom. The Er(3)-Co(2) bond length is 3.28 Å. Both Er(3)-Co(1) bond lengths are 2.88 Å. The Er(3)-Sn(1) bond length is 3.60 Å. The Er(3)-Sn(2) bond length is 3.22 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to two equivalent Er(1), two equivalent Er(2), four equivalent Er(3), and one Co(1) atom. The Co(1)-Co(1) bond length is 2.17 Å. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to two equivalent Er(2), two equivalent Er(3), four equivalent Er(1), and one Co(2) atom. The Co(2)-Co(2) bond length is 2.23 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a cuboctahedral geometry to four equivalent Er(1), four equivalent Er(2), and four equivalent Er(3) atoms. In the second Sn site, Sn(2) is bonded in a body-centered cubic geometry to four equivalent Er(2) and four equivalent Er(3) atoms.