Eu3(GeAs2)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one As(1), one As(3), two equivalent As(2), and two equivalent As(4) atoms to form a mixture of distorted corner and edge-sharing EuAs6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. In the second Eu site, Eu(2) is bonded to one As(2), one As(4), two equivalent As(1), and two equivalent As(3) atoms to form a mixture of distorted corner and edge-sharing EuAs6 octahedra. The corner-sharing octahedral tilt angles range from 2-5°. In the third Eu site, Eu(3) is bonded to one As(2), one As(4), two equivalent As(1), and two equivalent As(3) atoms to form a mixture of distorted corner and edge-sharing EuAs6 octahedra. The corner-sharing octahedral tilt angles range from 2-7°. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 4-coordinate geometry to one Ge(2), one As(1), one As(2), and one As(3) atom. In the second Ge site, Ge(2) is bonded in a 4-coordinate geometry to one Ge(1), one As(2), and two equivalent As(4) atoms. There are four inequivalent As sites. In the first As site, As(4) is bonded to one Eu(2), one Eu(3), two equivalent Eu(1), and two equivalent Ge(2) atoms to form AsEu4Ge2 octahedra that share corners with two equivalent As(2)Eu4Ge2 octahedra, corners with two equivalent As(3)Eu5Ge octahedra, corners with four equivalent As(1)Eu5Ge octahedra,  an edgeedge with one As(1)Eu5Ge octahedra, edges with two equivalent As(4)Eu4Ge2 octahedra, edges with two equivalent As(3)Eu5Ge octahedra, and edges with three equivalent As(2)Eu4Ge2 octahedra. The corner-sharing octahedral tilt angles range from 4-91°. In the second As site, As(1) is bonded to one Eu(1), two equivalent Eu(2), two equivalent Eu(3), and one Ge(1) atom to form AsEu5Ge octahedra that share  a cornercorner with one As(2)Eu4Ge2 octahedra, corners with two equivalent As(3)Eu5Ge octahedra, corners with four equivalent As(4)Eu4Ge2 octahedra,  an edgeedge with one As(4)Eu4Ge2 octahedra, edges with two equivalent As(1)Eu5Ge octahedra, edges with three equivalent As(2)Eu4Ge2 octahedra, and edges with four equivalent As(3)Eu5Ge octahedra. The corner-sharing octahedral tilt angles range from 2-86°. In the third As site, As(2) is bonded to one Eu(2), one Eu(3), two equivalent Eu(1), one Ge(1), and one Ge(2) atom to form AsEu4Ge2 octahedra that share  a cornercorner with one As(1)Eu5Ge octahedra, corners with two equivalent As(2)Eu4Ge2 octahedra, corners with two equivalent As(4)Eu4Ge2 octahedra, corners with three equivalent As(3)Eu5Ge octahedra, edges with two equivalent As(3)Eu5Ge octahedra, edges with three equivalent As(4)Eu4Ge2 octahedra, and edges with three equivalent As(1)Eu5Ge octahedra. The corner-sharing octahedral tilt angles range from 4-91°. In the fourth As site, As(3) is bonded to one Eu(1), two equivalent Eu(2), two equivalent Eu(3), and one Ge(1) atom to form AsEu5Ge octahedra that share corners with two equivalent As(4)Eu4Ge2 octahedra, corners with two equivalent As(1)Eu5Ge octahedra, corners with three equivalent As(2)Eu4Ge2 octahedra, edges with two equivalent As(2)Eu4Ge2 octahedra, edges with two equivalent As(4)Eu4Ge2 octahedra, edges with two equivalent As(3)Eu5Ge octahedra, and edges with four equivalent As(1)Eu5Ge octahedra. The corner-sharing octahedral tilt angles range from 2-91°.
Eu3(GeAs2)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one As(1), one As(3), two equivalent As(2), and two equivalent As(4) atoms to form a mixture of distorted corner and edge-sharing EuAs6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. The Eu(1)-As(1) bond length is 3.07 Å. The Eu(1)-As(3) bond length is 3.08 Å. There is one shorter (3.12 Å) and one longer (3.18 Å) Eu(1)-As(2) bond length. There is one shorter (3.13 Å) and one longer (3.15 Å) Eu(1)-As(4) bond length. In the second Eu site, Eu(2) is bonded to one As(2), one As(4), two equivalent As(1), and two equivalent As(3) atoms to form a mixture of distorted corner and edge-sharing EuAs6 octahedra. The corner-sharing octahedral tilt angles range from 2-5°. The Eu(2)-As(2) bond length is 3.15 Å. The Eu(2)-As(4) bond length is 3.21 Å. There is one shorter (3.08 Å) and one longer (3.09 Å) Eu(2)-As(1) bond length. There is one shorter (3.08 Å) and one longer (3.09 Å) Eu(2)-As(3) bond length. In the third Eu site, Eu(3) is bonded to one As(2), one As(4), two equivalent As(1), and two equivalent As(3) atoms to form a mixture of distorted corner and edge-sharing EuAs6 octahedra. The corner-sharing octahedral tilt angles range from 2-7°. The Eu(3)-As(2) bond length is 3.14 Å. The Eu(3)-As(4) bond length is 3.17 Å. There is one shorter (3.05 Å) and one longer (3.11 Å) Eu(3)-As(1) bond length. There is one shorter (3.08 Å) and one longer (3.09 Å) Eu(3)-As(3) bond length. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 4-coordinate geometry to one Ge(2), one As(1), one As(2), and one As(3) atom. The Ge(1)-Ge(2) bond length is 2.50 Å. The Ge(1)-As(1) bond length is 2.45 Å. The Ge(1)-As(2) bond length is 2.54 Å. The Ge(1)-As(3) bond length is 2.47 Å. In the second Ge site, Ge(2) is bonded in a 4-coordinate geometry to one Ge(1), one As(2), and two equivalent As(4) atoms. The Ge(2)-As(2) bond length is 2.49 Å. There is one shorter (2.51 Å) and one longer (2.53 Å) Ge(2)-As(4) bond length. There are four inequivalent As sites. In the first As site, As(4) is bonded to one Eu(2), one Eu(3), two equivalent Eu(1), and two equivalent Ge(2) atoms to form AsEu4Ge2 octahedra that share corners with two equivalent As(2)Eu4Ge2 octahedra, corners with two equivalent As(3)Eu5Ge octahedra, corners with four equivalent As(1)Eu5Ge octahedra,  an edgeedge with one As(1)Eu5Ge octahedra, edges with two equivalent As(4)Eu4Ge2 octahedra, edges with two equivalent As(3)Eu5Ge octahedra, and edges with three equivalent As(2)Eu4Ge2 octahedra. The corner-sharing octahedral tilt angles range from 4-91°. In the second As site, As(1) is bonded to one Eu(1), two equivalent Eu(2), two equivalent Eu(3), and one Ge(1) atom to form AsEu5Ge octahedra that share  a cornercorner with one As(2)Eu4Ge2 octahedra, corners with two equivalent As(3)Eu5Ge octahedra, corners with four equivalent As(4)Eu4Ge2 octahedra,  an edgeedge with one As(4)Eu4Ge2 octahedra, edges with two equivalent As(1)Eu5Ge octahedra, edges with three equivalent As(2)Eu4Ge2 octahedra, and edges with four equivalent As(3)Eu5Ge octahedra. The corner-sharing octahedral tilt angles range from 2-86°. In the third As site, As(2) is bonded to one Eu(2), one Eu(3), two equivalent Eu(1), one Ge(1), and one Ge(2) atom to form AsEu4Ge2 octahedra that share  a cornercorner with one As(1)Eu5Ge octahedra, corners with two equivalent As(2)Eu4Ge2 octahedra, corners with two equivalent As(4)Eu4Ge2 octahedra, corners with three equivalent As(3)Eu5Ge octahedra, edges with two equivalent As(3)Eu5Ge octahedra, edges with three equivalent As(4)Eu4Ge2 octahedra, and edges with three equivalent As(1)Eu5Ge octahedra. The corner-sharing octahedral tilt angles range from 4-91°. In the fourth As site, As(3) is bonded to one Eu(1), two equivalent Eu(2), two equivalent Eu(3), and one Ge(1) atom to form AsEu5Ge octahedra that share corners with two equivalent As(4)Eu4Ge2 octahedra, corners with two equivalent As(1)Eu5Ge octahedra, corners with three equivalent As(2)Eu4Ge2 octahedra, edges with two equivalent As(2)Eu4Ge2 octahedra, edges with two equivalent As(4)Eu4Ge2 octahedra, edges with two equivalent As(3)Eu5Ge octahedra, and edges with four equivalent As(1)Eu5Ge octahedra. The corner-sharing octahedral tilt angles range from 2-91°.