MgMn2(GeO3)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with two equivalent Ge(2)O4 tetrahedra, corners with four equivalent Ge(1)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with two equivalent Ge(1)O4 tetrahedra, corners with four equivalent Ge(2)O4 tetrahedra, and edges with two equivalent Mn(1)O6 octahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form GeO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra, and corners with two equivalent Ge(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 38-63°. In the second Ge site, Ge(2) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-63°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ge(1), and one Ge(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(2) and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Mn(1), and one Ge(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Ge(1) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Mn(1), one Mn(2), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing OMgMn2Ge tetrahedra.
MgMn2(GeO3)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms. Both Mg(1)-O(1) bond lengths are 2.19 Å. Both Mg(1)-O(4) bond lengths are 2.26 Å. Both Mg(1)-O(6) bond lengths are 2.11 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with two equivalent Ge(2)O4 tetrahedra, corners with four equivalent Ge(1)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. Both Mn(1)-O(4) bond lengths are 1.95 Å. Both Mn(1)-O(5) bond lengths are 1.97 Å. Both Mn(1)-O(6) bond lengths are 2.29 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with two equivalent Ge(1)O4 tetrahedra, corners with four equivalent Ge(2)O4 tetrahedra, and edges with two equivalent Mn(1)O6 octahedra. Both Mn(2)-O(3) bond lengths are 1.90 Å. Both Mn(2)-O(5) bond lengths are 2.24 Å. Both Mn(2)-O(6) bond lengths are 2.08 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form GeO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra, and corners with two equivalent Ge(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 38-63°. The Ge(1)-O(1) bond length is 1.82 Å. The Ge(1)-O(2) bond length is 1.77 Å. The Ge(1)-O(4) bond length is 1.76 Å. The Ge(1)-O(5) bond length is 1.75 Å. In the second Ge site, Ge(2) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-63°. The Ge(2)-O(1) bond length is 1.79 Å. The Ge(2)-O(2) bond length is 1.76 Å. The Ge(2)-O(3) bond length is 1.73 Å. The Ge(2)-O(6) bond length is 1.79 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ge(1), and one Ge(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(2) and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Mn(1), and one Ge(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Ge(1) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Mn(1), one Mn(2), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing OMgMn2Ge tetrahedra.