EuCuIn4 crystallizes in the orthorhombic Cmcm space group. Eu(1) is bonded in a 15-coordinate geometry to two equivalent Cu(1), three equivalent In(2), four equivalent In(1), and six equivalent In(3) atoms. Cu(1) is bonded in a 9-coordinate geometry to two equivalent Eu(1), one In(2), and six equivalent In(3) atoms. There are three inequivalent In sites. In the first In site, In(1) is bonded in a distorted q6 geometry to four equivalent Eu(1), two equivalent In(3), and four equivalent In(2) atoms. In the second In site, In(2) is bonded in a 2-coordinate geometry to three equivalent Eu(1), one Cu(1), and four equivalent In(1) atoms. In the third In site, In(3) is bonded in a 5-coordinate geometry to three equivalent Eu(1), three equivalent Cu(1), and one In(1) atom.
EuCuIn4 crystallizes in the orthorhombic Cmcm space group. Eu(1) is bonded in a 15-coordinate geometry to two equivalent Cu(1), three equivalent In(2), four equivalent In(1), and six equivalent In(3) atoms. Both Eu(1)-Cu(1) bond lengths are 3.44 Å. There is one shorter (3.26 Å) and two longer (3.78 Å) Eu(1)-In(2) bond lengths. All Eu(1)-In(1) bond lengths are 3.56 Å. There are four shorter (3.35 Å) and two longer (3.61 Å) Eu(1)-In(3) bond lengths. Cu(1) is bonded in a 9-coordinate geometry to two equivalent Eu(1), one In(2), and six equivalent In(3) atoms. The Cu(1)-In(2) bond length is 2.64 Å. There are two shorter (2.66 Å) and four longer (2.79 Å) Cu(1)-In(3) bond lengths. There are three inequivalent In sites. In the first In site, In(1) is bonded in a distorted q6 geometry to four equivalent Eu(1), two equivalent In(3), and four equivalent In(2) atoms. Both In(1)-In(3) bond lengths are 3.18 Å. All In(1)-In(2) bond lengths are 3.16 Å. In the second In site, In(2) is bonded in a 2-coordinate geometry to three equivalent Eu(1), one Cu(1), and four equivalent In(1) atoms. In the third In site, In(3) is bonded in a 5-coordinate geometry to three equivalent Eu(1), three equivalent Cu(1), and one In(1) atom.