Na4MgTi2(GeO5)2 crystallizes in the tetragonal P-4m2 space group. Na(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Mg(1) is bonded to four equivalent O(2) atoms to form MgO4 tetrahedra that share corners with four equivalent Ti(1)O5 trigonal bipyramids and edges with two equivalent Ge(1)O4 tetrahedra. Ti(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Ge(1)O4 tetrahedra, and corners with two equivalent Ge(2)O4 tetrahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to four equivalent O(2) atoms to form distorted GeO4 tetrahedra that share corners with four equivalent Ti(1)O5 trigonal bipyramids and edges with two equivalent Mg(1)O4 tetrahedra. In the second Ge site, Ge(2) is bonded to four equivalent O(1) atoms to form GeO4 tetrahedra that share corners with four equivalent Ti(1)O5 trigonal bipyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Ti(1), and one Ge(2) atom. In the second O site, O(2) is bonded to two equivalent Na(1), one Mg(1), one Ti(1), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing ONa2MgTiGe trigonal bipyramids. In the third O site, O(3) is bonded in a single-bond geometry to one Ti(1) atom.
Na4MgTi2(GeO5)2 crystallizes in the tetragonal P-4m2 space group. Na(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Na(1)-O(1) bond lengths are 2.24 Å. Both Na(1)-O(2) bond lengths are 2.33 Å. Mg(1) is bonded to four equivalent O(2) atoms to form MgO4 tetrahedra that share corners with four equivalent Ti(1)O5 trigonal bipyramids and edges with two equivalent Ge(1)O4 tetrahedra. All Mg(1)-O(2) bond lengths are 2.01 Å. Ti(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Ge(1)O4 tetrahedra, and corners with two equivalent Ge(2)O4 tetrahedra. The Ti(1)-O(3) bond length is 1.72 Å. Both Ti(1)-O(1) bond lengths are 2.05 Å. Both Ti(1)-O(2) bond lengths are 2.02 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to four equivalent O(2) atoms to form distorted GeO4 tetrahedra that share corners with four equivalent Ti(1)O5 trigonal bipyramids and edges with two equivalent Mg(1)O4 tetrahedra. All Ge(1)-O(2) bond lengths are 2.20 Å. In the second Ge site, Ge(2) is bonded to four equivalent O(1) atoms to form GeO4 tetrahedra that share corners with four equivalent Ti(1)O5 trigonal bipyramids. All Ge(2)-O(1) bond lengths are 1.78 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Ti(1), and one Ge(2) atom. In the second O site, O(2) is bonded to two equivalent Na(1), one Mg(1), one Ti(1), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing ONa2MgTiGe trigonal bipyramids. In the third O site, O(3) is bonded in a single-bond geometry to one Ti(1) atom.