La2GeO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(5), three equivalent O(1), and three equivalent O(4) atoms. In the second La site, La(2) is bonded to one O(5), three equivalent O(2), and three equivalent O(3) atoms to form distorted LaO7 hexagonal pyramids that share corners with two equivalent Ge(1)O4 tetrahedra, edges with six equivalent La(2)O7 hexagonal pyramids, and  an edgeedge with one Ge(1)O4 tetrahedra. 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 corners with two equivalent La(2)O7 hexagonal pyramids and  an edgeedge with one La(2)O7 hexagonal pyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to three equivalent La(1) and one Ge(1) atom. In the second O site, O(2) is bonded to three equivalent La(2) and one Ge(1) atom to form distorted OLa3Ge tetrahedra that share corners with two equivalent O(5)La3Ge tetrahedra, corners with four equivalent O(2)La3Ge tetrahedra, corners with five equivalent O(3)La4 tetrahedra,  an edgeedge with one O(2)La3Ge tetrahedra,  an edgeedge with one O(5)La3Ge tetrahedra, and edges with two equivalent O(3)La4 tetrahedra. In the third O site, O(3) is bonded to one La(1) and three equivalent La(2) atoms to form OLa4 tetrahedra that share  a cornercorner with one O(5)La3Ge tetrahedra, corners with four equivalent O(3)La4 tetrahedra, corners with five equivalent O(2)La3Ge tetrahedra,  an edgeedge with one O(3)La4 tetrahedra, edges with two equivalent O(2)La3Ge tetrahedra, and edges with two equivalent O(5)La3Ge tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to three equivalent La(1) and one Ge(1) atom. In the fifth O site, O(5) is bonded to one La(2), two equivalent La(1), and one Ge(1) atom to form distorted OLa3Ge tetrahedra that share  a cornercorner with one O(3)La4 tetrahedra, corners with two equivalent O(2)La3Ge tetrahedra, corners with two equivalent O(5)La3Ge tetrahedra,  an edgeedge with one O(2)La3Ge tetrahedra, and edges with two equivalent O(3)La4 tetrahedra.
La2GeO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(5), three equivalent O(1), and three equivalent O(4) atoms. The La(1)-O(3) bond length is 2.48 Å. There is one shorter (2.40 Å) and one longer (2.62 Å) La(1)-O(5) bond length. There are a spread of La(1)-O(1) bond distances ranging from 2.56-2.92 Å. There are a spread of La(1)-O(4) bond distances ranging from 2.45-2.72 Å. In the second La site, La(2) is bonded to one O(5), three equivalent O(2), and three equivalent O(3) atoms to form distorted LaO7 hexagonal pyramids that share corners with two equivalent Ge(1)O4 tetrahedra, edges with six equivalent La(2)O7 hexagonal pyramids, and  an edgeedge with one Ge(1)O4 tetrahedra. The La(2)-O(5) bond length is 2.50 Å. There is one shorter (2.47 Å) and two longer (2.63 Å) La(2)-O(2) bond lengths. There are a spread of La(2)-O(3) bond distances ranging from 2.40-2.44 Å. 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 corners with two equivalent La(2)O7 hexagonal pyramids and  an edgeedge with one La(2)O7 hexagonal pyramid. The Ge(1)-O(1) bond length is 1.72 Å. The Ge(1)-O(2) bond length is 1.77 Å. The Ge(1)-O(4) bond length is 1.75 Å. The Ge(1)-O(5) bond length is 1.78 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to three equivalent La(1) and one Ge(1) atom. In the second O site, O(2) is bonded to three equivalent La(2) and one Ge(1) atom to form distorted OLa3Ge tetrahedra that share corners with two equivalent O(5)La3Ge tetrahedra, corners with four equivalent O(2)La3Ge tetrahedra, corners with five equivalent O(3)La4 tetrahedra,  an edgeedge with one O(2)La3Ge tetrahedra,  an edgeedge with one O(5)La3Ge tetrahedra, and edges with two equivalent O(3)La4 tetrahedra. In the third O site, O(3) is bonded to one La(1) and three equivalent La(2) atoms to form OLa4 tetrahedra that share  a cornercorner with one O(5)La3Ge tetrahedra, corners with four equivalent O(3)La4 tetrahedra, corners with five equivalent O(2)La3Ge tetrahedra,  an edgeedge with one O(3)La4 tetrahedra, edges with two equivalent O(2)La3Ge tetrahedra, and edges with two equivalent O(5)La3Ge tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to three equivalent La(1) and one Ge(1) atom. In the fifth O site, O(5) is bonded to one La(2), two equivalent La(1), and one Ge(1) atom to form distorted OLa3Ge tetrahedra that share  a cornercorner with one O(3)La4 tetrahedra, corners with two equivalent O(2)La3Ge tetrahedra, corners with two equivalent O(5)La3Ge tetrahedra,  an edgeedge with one O(2)La3Ge tetrahedra, and edges with two equivalent O(3)La4 tetrahedra.