Na2MgGe2(SbO5)2 crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(8), and one O(9) atom. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(3), one O(5), one O(7), and one O(9) atom. Mg(1) is bonded to one O(1), one O(10), one O(4), one O(5), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share corners with two equivalent Sb(2)O6 octahedra, corners with two equivalent Ge(2)O4 tetrahedra,  an edgeedge with one Sb(1)O6 octahedra,  an edgeedge with one Sb(2)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-53°. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(10), one O(3), one O(4), and one O(9) atom to form GeO4 tetrahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 41-63°. In the second Ge site, Ge(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form GeO4 tetrahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, and corners with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 35-66°. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(9) atom to form SbO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 45°. In the second Sb site, Sb(2) is bonded to one O(1), one O(10), one O(2), one O(4), one O(6), and one O(8) atom to form distorted SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 45°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Mg(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Na(2), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Ge(1), and one Sb(1) atom to form distorted ONa2GeSb trigonal pyramids that share corners with two equivalent O(10)NaMgGeSb tetrahedra,  a cornercorner with one O(5)Na2MgGeSb trigonal bipyramid, and  an edgeedge with one O(5)Na2MgGeSb trigonal bipyramid. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Ge(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded to one Na(1), one Na(2), one Mg(1), one Ge(2), and one Sb(1) atom to form distorted ONa2MgGeSb trigonal bipyramids that share corners with two equivalent O(10)NaMgGeSb tetrahedra,  a cornercorner with one O(3)Na2GeSb trigonal pyramid, and  an edgeedge with one O(3)Na2GeSb trigonal pyramid. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Na(1), one Ge(2), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(2), one Ge(2), and one Sb(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Na(1), one Mg(1), one Ge(2), and one Sb(2) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Ge(1), and one Sb(1) atom. In the tenth O site, O(10) is bonded to one Na(2), one Mg(1), one Ge(1), and one Sb(2) atom to form distorted ONaMgGeSb tetrahedra that share corners with two equivalent O(5)Na2MgGeSb trigonal bipyramids and corners with two equivalent O(3)Na2GeSb trigonal pyramids.
Na2MgGe2(SbO5)2 crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(8), and one O(9) atom. The Na(1)-O(1) bond length is 2.33 Å. The Na(1)-O(3) bond length is 2.46 Å. The Na(1)-O(5) bond length is 2.64 Å. The Na(1)-O(6) bond length is 2.41 Å. The Na(1)-O(8) bond length is 2.34 Å. The Na(1)-O(9) bond length is 2.66 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(3), one O(5), one O(7), and one O(9) atom. The Na(2)-O(10) bond length is 2.33 Å. The Na(2)-O(2) bond length is 2.32 Å. The Na(2)-O(3) bond length is 2.39 Å. The Na(2)-O(5) bond length is 2.74 Å. The Na(2)-O(7) bond length is 2.57 Å. The Na(2)-O(9) bond length is 2.70 Å. Mg(1) is bonded to one O(1), one O(10), one O(4), one O(5), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share corners with two equivalent Sb(2)O6 octahedra, corners with two equivalent Ge(2)O4 tetrahedra,  an edgeedge with one Sb(1)O6 octahedra,  an edgeedge with one Sb(2)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-53°. The Mg(1)-O(1) bond length is 2.07 Å. The Mg(1)-O(10) bond length is 2.04 Å. The Mg(1)-O(4) bond length is 2.09 Å. The Mg(1)-O(5) bond length is 2.14 Å. The Mg(1)-O(8) bond length is 2.00 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(10), one O(3), one O(4), and one O(9) atom to form GeO4 tetrahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 41-63°. The Ge(1)-O(10) bond length is 1.83 Å. The Ge(1)-O(3) bond length is 1.79 Å. The Ge(1)-O(4) bond length is 1.76 Å. The Ge(1)-O(9) bond length is 1.80 Å. In the second Ge site, Ge(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form GeO4 tetrahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, and corners with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 35-66°. The Ge(2)-O(5) bond length is 1.84 Å. The Ge(2)-O(6) bond length is 1.78 Å. The Ge(2)-O(7) bond length is 1.82 Å. The Ge(2)-O(8) bond length is 1.77 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(9) atom to form SbO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 45°. The Sb(1)-O(1) bond length is 1.95 Å. The Sb(1)-O(2) bond length is 1.95 Å. The Sb(1)-O(3) bond length is 2.05 Å. The Sb(1)-O(5) bond length is 2.21 Å. The Sb(1)-O(7) bond length is 2.07 Å. The Sb(1)-O(9) bond length is 2.04 Å. In the second Sb site, Sb(2) is bonded to one O(1), one O(10), one O(2), one O(4), one O(6), and one O(8) atom to form distorted SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 45°. The Sb(2)-O(1) bond length is 2.54 Å. The Sb(2)-O(10) bond length is 2.18 Å. The Sb(2)-O(2) bond length is 2.10 Å. The Sb(2)-O(4) bond length is 2.45 Å. The Sb(2)-O(6) bond length is 2.16 Å. The Sb(2)-O(8) bond length is 2.52 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Mg(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Na(2), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Ge(1), and one Sb(1) atom to form distorted ONa2GeSb trigonal pyramids that share corners with two equivalent O(10)NaMgGeSb tetrahedra,  a cornercorner with one O(5)Na2MgGeSb trigonal bipyramid, and  an edgeedge with one O(5)Na2MgGeSb trigonal bipyramid. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Ge(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded to one Na(1), one Na(2), one Mg(1), one Ge(2), and one Sb(1) atom to form distorted ONa2MgGeSb trigonal bipyramids that share corners with two equivalent O(10)NaMgGeSb tetrahedra,  a cornercorner with one O(3)Na2GeSb trigonal pyramid, and  an edgeedge with one O(3)Na2GeSb trigonal pyramid. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Na(1), one Ge(2), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(2), one Ge(2), and one Sb(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Na(1), one Mg(1), one Ge(2), and one Sb(2) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Ge(1), and one Sb(1) atom. In the tenth O site, O(10) is bonded to one Na(2), one Mg(1), one Ge(1), and one Sb(2) atom to form distorted ONaMgGeSb tetrahedra that share corners with two equivalent O(5)Na2MgGeSb trigonal bipyramids and corners with two equivalent O(3)Na2GeSb trigonal pyramids.