Mg7Pr4Ge6 crystallizes in the monoclinic C2/m space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ge(2) and two equivalent Ge(3) atoms to form distorted MgGe4 tetrahedra that share corners with four equivalent Pr(2)Ge6 octahedra, corners with two equivalent Mg(1)Ge4 tetrahedra, corners with two equivalent Mg(2)Ge4 tetrahedra, corners with two equivalent Mg(3)Ge4 tetrahedra, edges with two equivalent Pr(2)Ge6 octahedra,  an edgeedge with one Mg(1)Ge4 tetrahedra,  an edgeedge with one Mg(2)Ge4 tetrahedra, and edges with two equivalent Mg(3)Ge4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-57°. In the second Mg site, Mg(2) is bonded to two equivalent Ge(1) and two equivalent Ge(3) atoms to form distorted MgGe4 tetrahedra that share corners with two equivalent Pr(2)Ge6 octahedra, corners with two equivalent Mg(1)Ge4 tetrahedra, corners with two equivalent Mg(2)Ge4 tetrahedra, corners with four equivalent Mg(3)Ge4 tetrahedra, edges with two equivalent Pr(2)Ge6 octahedra,  an edgeedge with one Mg(1)Ge4 tetrahedra, and  an edgeedge with one Mg(2)Ge4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. In the third Mg site, Mg(3) is bonded to one Ge(1), one Ge(3), and two equivalent Ge(2) atoms to form distorted MgGe4 tetrahedra that share corners with three equivalent Pr(2)Ge6 octahedra, corners with two equivalent Mg(1)Ge4 tetrahedra, corners with two equivalent Mg(3)Ge4 tetrahedra, corners with four equivalent Mg(2)Ge4 tetrahedra, edges with three equivalent Pr(2)Ge6 octahedra, and edges with two equivalent Mg(1)Ge4 tetrahedra. The corner-sharing octahedral tilt angles range from 17-63°. In the fourth Mg site, Mg(4) is bonded in a distorted square co-planar geometry to four equivalent Ge(1) atoms. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 5-coordinate geometry to two equivalent Ge(1) and three equivalent Ge(3) atoms. In the second Pr site, Pr(2) is bonded to one Ge(3), two equivalent Ge(1), and three equivalent Ge(2) atoms to form distorted PrGe6 octahedra that share corners with two equivalent Mg(2)Ge4 tetrahedra, corners with three equivalent Mg(3)Ge4 tetrahedra, corners with four equivalent Mg(1)Ge4 tetrahedra, edges with four equivalent Pr(2)Ge6 octahedra, edges with two equivalent Mg(1)Ge4 tetrahedra, edges with two equivalent Mg(2)Ge4 tetrahedra, and edges with three equivalent Mg(3)Ge4 tetrahedra. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to one Mg(3), two equivalent Mg(2), two equivalent Mg(4), two equivalent Pr(1), and two equivalent Pr(2) atoms. In the second Ge site, Ge(2) is bonded in a 7-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), and three equivalent Pr(2) atoms. In the third Ge site, Ge(3) is bonded in a 9-coordinate geometry to one Mg(3), two equivalent Mg(1), two equivalent Mg(2), one Pr(2), and three equivalent Pr(1) atoms.
Mg7Pr4Ge6 crystallizes in the monoclinic C2/m space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ge(2) and two equivalent Ge(3) atoms to form distorted MgGe4 tetrahedra that share corners with four equivalent Pr(2)Ge6 octahedra, corners with two equivalent Mg(1)Ge4 tetrahedra, corners with two equivalent Mg(2)Ge4 tetrahedra, corners with two equivalent Mg(3)Ge4 tetrahedra, edges with two equivalent Pr(2)Ge6 octahedra,  an edgeedge with one Mg(1)Ge4 tetrahedra,  an edgeedge with one Mg(2)Ge4 tetrahedra, and edges with two equivalent Mg(3)Ge4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-57°. There is one shorter (2.69 Å) and one longer (2.84 Å) Mg(1)-Ge(2) bond length. Both Mg(1)-Ge(3) bond lengths are 2.87 Å. In the second Mg site, Mg(2) is bonded to two equivalent Ge(1) and two equivalent Ge(3) atoms to form distorted MgGe4 tetrahedra that share corners with two equivalent Pr(2)Ge6 octahedra, corners with two equivalent Mg(1)Ge4 tetrahedra, corners with two equivalent Mg(2)Ge4 tetrahedra, corners with four equivalent Mg(3)Ge4 tetrahedra, edges with two equivalent Pr(2)Ge6 octahedra,  an edgeedge with one Mg(1)Ge4 tetrahedra, and  an edgeedge with one Mg(2)Ge4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. There is one shorter (2.77 Å) and one longer (2.80 Å) Mg(2)-Ge(1) bond length. Both Mg(2)-Ge(3) bond lengths are 2.74 Å. In the third Mg site, Mg(3) is bonded to one Ge(1), one Ge(3), and two equivalent Ge(2) atoms to form distorted MgGe4 tetrahedra that share corners with three equivalent Pr(2)Ge6 octahedra, corners with two equivalent Mg(1)Ge4 tetrahedra, corners with two equivalent Mg(3)Ge4 tetrahedra, corners with four equivalent Mg(2)Ge4 tetrahedra, edges with three equivalent Pr(2)Ge6 octahedra, and edges with two equivalent Mg(1)Ge4 tetrahedra. The corner-sharing octahedral tilt angles range from 17-63°. The Mg(3)-Ge(1) bond length is 2.80 Å. The Mg(3)-Ge(3) bond length is 2.93 Å. Both Mg(3)-Ge(2) bond lengths are 2.61 Å. In the fourth Mg site, Mg(4) is bonded in a distorted square co-planar geometry to four equivalent Ge(1) atoms. All Mg(4)-Ge(1) bond lengths are 2.90 Å. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 5-coordinate geometry to two equivalent Ge(1) and three equivalent Ge(3) atoms. Both Pr(1)-Ge(1) bond lengths are 3.12 Å. There are two shorter (3.19 Å) and one longer (3.21 Å) Pr(1)-Ge(3) bond length. In the second Pr site, Pr(2) is bonded to one Ge(3), two equivalent Ge(1), and three equivalent Ge(2) atoms to form distorted PrGe6 octahedra that share corners with two equivalent Mg(2)Ge4 tetrahedra, corners with three equivalent Mg(3)Ge4 tetrahedra, corners with four equivalent Mg(1)Ge4 tetrahedra, edges with four equivalent Pr(2)Ge6 octahedra, edges with two equivalent Mg(1)Ge4 tetrahedra, edges with two equivalent Mg(2)Ge4 tetrahedra, and edges with three equivalent Mg(3)Ge4 tetrahedra. The Pr(2)-Ge(3) bond length is 3.36 Å. Both Pr(2)-Ge(1) bond lengths are 3.19 Å. There are two shorter (3.11 Å) and one longer (3.16 Å) Pr(2)-Ge(2) bond length. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to one Mg(3), two equivalent Mg(2), two equivalent Mg(4), two equivalent Pr(1), and two equivalent Pr(2) atoms. In the second Ge site, Ge(2) is bonded in a 7-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), and three equivalent Pr(2) atoms. In the third Ge site, Ge(3) is bonded in a 9-coordinate geometry to one Mg(3), two equivalent Mg(1), two equivalent Mg(2), one Pr(2), and three equivalent Pr(1) atoms.