Cu2In crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 14-coordinate geometry to two equivalent Cu(1), six equivalent Cu(2), and six equivalent In(1) atoms. In the second Cu site, Cu(2) is bonded to six equivalent Cu(1) and five equivalent In(1) atoms to form a mixture of distorted corner and face-sharing CuIn5Cu6 trigonal bipyramids. In(1) is bonded in a 11-coordinate geometry to five equivalent Cu(2) and six equivalent Cu(1) atoms.
Cu2In crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 14-coordinate geometry to two equivalent Cu(1), six equivalent Cu(2), and six equivalent In(1) atoms. Both Cu(1)-Cu(1) bond lengths are 2.68 Å. All Cu(1)-Cu(2) bond lengths are 2.90 Å. All Cu(1)-In(1) bond lengths are 2.90 Å. In the second Cu site, Cu(2) is bonded to six equivalent Cu(1) and five equivalent In(1) atoms to form a mixture of distorted corner and face-sharing CuIn5Cu6 trigonal bipyramids. There are three shorter (2.57 Å) and two longer (2.68 Å) Cu(2)-In(1) bond lengths. In(1) is bonded in a 11-coordinate geometry to five equivalent Cu(2) and six equivalent Cu(1) atoms.