BeNdCu4 crystallizes in the hexagonal P-6m2 space group. Be(1) is bonded in a 6-coordinate geometry to three equivalent Nd(1) and six equivalent Cu(2) atoms. Nd(1) is bonded in a 18-coordinate geometry to three equivalent Be(1), three equivalent Cu(1), and twelve equivalent Cu(2) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to three equivalent Nd(1) and six equivalent Cu(2) atoms to form distorted CuNd3Cu6 cuboctahedra that share corners with six equivalent Cu(1)Nd3Cu6 cuboctahedra, corners with twelve equivalent Cu(2)Nd4Be2Cu6 cuboctahedra, edges with twelve equivalent Cu(2)Nd4Be2Cu6 cuboctahedra, faces with two equivalent Cu(1)Nd3Cu6 cuboctahedra, and faces with six equivalent Cu(2)Nd4Be2Cu6 cuboctahedra. In the second Cu site, Cu(2) is bonded to two equivalent Be(1), four equivalent Nd(1), two equivalent Cu(1), and four equivalent Cu(2) atoms to form distorted CuNd4Be2Cu6 cuboctahedra that share corners with four equivalent Cu(1)Nd3Cu6 cuboctahedra, corners with sixteen equivalent Cu(2)Nd4Be2Cu6 cuboctahedra, edges with four equivalent Cu(1)Nd3Cu6 cuboctahedra, edges with ten equivalent Cu(2)Nd4Be2Cu6 cuboctahedra, faces with two equivalent Cu(1)Nd3Cu6 cuboctahedra, and faces with ten equivalent Cu(2)Nd4Be2Cu6 cuboctahedra.
BeNdCu4 crystallizes in the hexagonal P-6m2 space group. Be(1) is bonded in a 6-coordinate geometry to three equivalent Nd(1) and six equivalent Cu(2) atoms. All Be(1)-Nd(1) bond lengths are 2.98 Å. All Be(1)-Cu(2) bond lengths are 2.41 Å. Nd(1) is bonded in a 18-coordinate geometry to three equivalent Be(1), three equivalent Cu(1), and twelve equivalent Cu(2) atoms. All Nd(1)-Cu(1) bond lengths are 2.98 Å. All Nd(1)-Cu(2) bond lengths are 3.22 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to three equivalent Nd(1) and six equivalent Cu(2) atoms to form distorted CuNd3Cu6 cuboctahedra that share corners with six equivalent Cu(1)Nd3Cu6 cuboctahedra, corners with twelve equivalent Cu(2)Nd4Be2Cu6 cuboctahedra, edges with twelve equivalent Cu(2)Nd4Be2Cu6 cuboctahedra, faces with two equivalent Cu(1)Nd3Cu6 cuboctahedra, and faces with six equivalent Cu(2)Nd4Be2Cu6 cuboctahedra. All Cu(1)-Cu(2) bond lengths are 2.46 Å. In the second Cu site, Cu(2) is bonded to two equivalent Be(1), four equivalent Nd(1), two equivalent Cu(1), and four equivalent Cu(2) atoms to form distorted CuNd4Be2Cu6 cuboctahedra that share corners with four equivalent Cu(1)Nd3Cu6 cuboctahedra, corners with sixteen equivalent Cu(2)Nd4Be2Cu6 cuboctahedra, edges with four equivalent Cu(1)Nd3Cu6 cuboctahedra, edges with ten equivalent Cu(2)Nd4Be2Cu6 cuboctahedra, faces with two equivalent Cu(1)Nd3Cu6 cuboctahedra, and faces with ten equivalent Cu(2)Nd4Be2Cu6 cuboctahedra. There are two shorter (2.50 Å) and two longer (2.66 Å) Cu(2)-Cu(2) bond lengths.