Er3(CoIn2)2 crystallizes in the hexagonal P-6 space group. Er(1) is bonded in a 10-coordinate geometry to one Co(2), two equivalent Co(1), one In(1), and six equivalent In(2) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 6-coordinate geometry to six equivalent Er(1) and three equivalent In(2) atoms. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to three equivalent Er(1) and six equivalent In(2) atoms. There are two inequivalent In sites. In the first In site, In(1) is bonded in a trigonal planar geometry to three equivalent Er(1) and six equivalent In(2) atoms. In the second In site, In(2) is bonded in a 11-coordinate geometry to six equivalent Er(1), one Co(1), two equivalent Co(2), and two equivalent In(1) atoms.
Er3(CoIn2)2 crystallizes in the hexagonal P-6 space group. Er(1) is bonded in a 10-coordinate geometry to one Co(2), two equivalent Co(1), one In(1), and six equivalent In(2) atoms. The Er(1)-Co(2) bond length is 3.06 Å. Both Er(1)-Co(1) bond lengths are 2.70 Å. The Er(1)-In(1) bond length is 3.02 Å. There are a spread of Er(1)-In(2) bond distances ranging from 3.15-3.44 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 6-coordinate geometry to six equivalent Er(1) and three equivalent In(2) atoms. All Co(1)-In(2) bond lengths are 3.18 Å. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to three equivalent Er(1) and six equivalent In(2) atoms. All Co(2)-In(2) bond lengths are 2.80 Å. There are two inequivalent In sites. In the first In site, In(1) is bonded in a trigonal planar geometry to three equivalent Er(1) and six equivalent In(2) atoms. All In(1)-In(2) bond lengths are 3.28 Å. In the second In site, In(2) is bonded in a 11-coordinate geometry to six equivalent Er(1), one Co(1), two equivalent Co(2), and two equivalent In(1) atoms.