Ba2TiGe2O8 crystallizes in the tetragonal P4bm space group. Ba(1) is bonded in a 8-coordinate geometry to one O(4), three equivalent O(2), and four equivalent O(3) atoms. Ti(1) is bonded in a 5-coordinate geometry to one O(1) and four equivalent O(3) atoms. Ge(1) is bonded to one O(2), one O(4), and two equivalent O(3) atoms to form corner-sharing GeO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Ti(1) atom. In the second O site, O(2) is bonded to three equivalent Ba(1) and one Ge(1) atom to form distorted OBa3Ge tetrahedra that share corners with two equivalent O(4)Ba2Ge2 tetrahedra, corners with four equivalent O(2)Ba3Ge tetrahedra,  an edgeedge with one O(4)Ba2Ge2 tetrahedra, and  an edgeedge with one O(2)Ba3Ge tetrahedra. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Ti(1), and one Ge(1) atom. In the fourth O site, O(4) is bonded to two equivalent Ba(1) and two equivalent Ge(1) atoms to form a mixture of distorted corner and edge-sharing OBa2Ge2 tetrahedra.
Ba2TiGe2O8 crystallizes in the tetragonal P4bm space group. Ba(1) is bonded in a 8-coordinate geometry to one O(4), three equivalent O(2), and four equivalent O(3) atoms. The Ba(1)-O(4) bond length is 2.84 Å. There is one shorter (2.75 Å) and two longer (2.92 Å) Ba(1)-O(2) bond lengths. There are two shorter (2.84 Å) and two longer (3.08 Å) Ba(1)-O(3) bond lengths. Ti(1) is bonded in a 5-coordinate geometry to one O(1) and four equivalent O(3) atoms. The Ti(1)-O(1) bond length is 1.70 Å. All Ti(1)-O(3) bond lengths are 1.99 Å. Ge(1) is bonded to one O(2), one O(4), and two equivalent O(3) atoms to form corner-sharing GeO4 tetrahedra. The Ge(1)-O(2) bond length is 1.73 Å. The Ge(1)-O(4) bond length is 1.82 Å. Both Ge(1)-O(3) bond lengths are 1.77 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Ti(1) atom. In the second O site, O(2) is bonded to three equivalent Ba(1) and one Ge(1) atom to form distorted OBa3Ge tetrahedra that share corners with two equivalent O(4)Ba2Ge2 tetrahedra, corners with four equivalent O(2)Ba3Ge tetrahedra,  an edgeedge with one O(4)Ba2Ge2 tetrahedra, and  an edgeedge with one O(2)Ba3Ge tetrahedra. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Ti(1), and one Ge(1) atom. In the fourth O site, O(4) is bonded to two equivalent Ba(1) and two equivalent Ge(1) atoms to form a mixture of distorted corner and edge-sharing OBa2Ge2 tetrahedra.