Eu2Cd2As3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one As(2), two equivalent As(1), and three equivalent As(3) atoms to form distorted EuAs6 octahedra that share corners with three equivalent Cd(1)Eu2As4 tetrahedra, corners with four equivalent Cd(2)EuAs4 tetrahedra, edges with four equivalent Eu(1)As6 octahedra, edges with two equivalent Cd(2)EuAs4 tetrahedra, and edges with three equivalent Cd(1)Eu2As4 tetrahedra. In the second Eu site, Eu(2) is bonded in a 10-coordinate geometry to one Cd(2), two equivalent Cd(1), three equivalent As(2), and four equivalent As(1) atoms. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to two equivalent Eu(2), one As(1), one As(2), and two equivalent As(3) atoms to form distorted CdEu2As4 tetrahedra that share corners with three equivalent Eu(1)As6 octahedra, corners with two equivalent Cd(2)EuAs4 tetrahedra, edges with three equivalent Eu(1)As6 octahedra, edges with two equivalent Cd(1)Eu2As4 tetrahedra, and faces with two equivalent Cd(2)EuAs4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-56°. In the second Cd site, Cd(2) is bonded to one Eu(2), two equivalent As(2), and two equivalent As(3) atoms to form distorted CdEuAs4 tetrahedra that share corners with four equivalent Eu(1)As6 octahedra, corners with two equivalent Cd(1)Eu2As4 tetrahedra, corners with two equivalent Cd(2)EuAs4 tetrahedra, edges with two equivalent Eu(1)As6 octahedra,  an edgeedge with one Cd(2)EuAs4 tetrahedra, and faces with two equivalent Cd(1)Eu2As4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-58°. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to two equivalent Eu(1), four equivalent Eu(2), one Cd(1), and one As(1) atom. In the second As site, As(2) is bonded in a 7-coordinate geometry to one Eu(1), three equivalent Eu(2), one Cd(1), and two equivalent Cd(2) atoms. In the third As site, As(3) is bonded to three equivalent Eu(1), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted edge-sharing AsEu3Cd4 pentagonal bipyramids.
Eu2Cd2As3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one As(2), two equivalent As(1), and three equivalent As(3) atoms to form distorted EuAs6 octahedra that share corners with three equivalent Cd(1)Eu2As4 tetrahedra, corners with four equivalent Cd(2)EuAs4 tetrahedra, edges with four equivalent Eu(1)As6 octahedra, edges with two equivalent Cd(2)EuAs4 tetrahedra, and edges with three equivalent Cd(1)Eu2As4 tetrahedra. The Eu(1)-As(2) bond length is 3.19 Å. Both Eu(1)-As(1) bond lengths are 3.18 Å. There is one shorter (3.06 Å) and two longer (3.10 Å) Eu(1)-As(3) bond lengths. In the second Eu site, Eu(2) is bonded in a 10-coordinate geometry to one Cd(2), two equivalent Cd(1), three equivalent As(2), and four equivalent As(1) atoms. The Eu(2)-Cd(2) bond length is 3.50 Å. Both Eu(2)-Cd(1) bond lengths are 3.51 Å. There is one shorter (3.10 Å) and two longer (3.22 Å) Eu(2)-As(2) bond lengths. There are two shorter (3.22 Å) and two longer (3.46 Å) Eu(2)-As(1) bond lengths. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to two equivalent Eu(2), one As(1), one As(2), and two equivalent As(3) atoms to form distorted CdEu2As4 tetrahedra that share corners with three equivalent Eu(1)As6 octahedra, corners with two equivalent Cd(2)EuAs4 tetrahedra, edges with three equivalent Eu(1)As6 octahedra, edges with two equivalent Cd(1)Eu2As4 tetrahedra, and faces with two equivalent Cd(2)EuAs4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-56°. The Cd(1)-As(1) bond length is 2.79 Å. The Cd(1)-As(2) bond length is 2.77 Å. Both Cd(1)-As(3) bond lengths are 2.73 Å. In the second Cd site, Cd(2) is bonded to one Eu(2), two equivalent As(2), and two equivalent As(3) atoms to form distorted CdEuAs4 tetrahedra that share corners with four equivalent Eu(1)As6 octahedra, corners with two equivalent Cd(1)Eu2As4 tetrahedra, corners with two equivalent Cd(2)EuAs4 tetrahedra, edges with two equivalent Eu(1)As6 octahedra,  an edgeedge with one Cd(2)EuAs4 tetrahedra, and faces with two equivalent Cd(1)Eu2As4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-58°. Both Cd(2)-As(2) bond lengths are 2.75 Å. There is one shorter (2.70 Å) and one longer (2.95 Å) Cd(2)-As(3) bond length. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to two equivalent Eu(1), four equivalent Eu(2), one Cd(1), and one As(1) atom. The As(1)-As(1) bond length is 2.56 Å. In the second As site, As(2) is bonded in a 7-coordinate geometry to one Eu(1), three equivalent Eu(2), one Cd(1), and two equivalent Cd(2) atoms. In the third As site, As(3) is bonded to three equivalent Eu(1), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted edge-sharing AsEu3Cd4 pentagonal bipyramids.