YAlGeO5 crystallizes in the orthorhombic Pbam space group. Y(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), and four equivalent O(3) atoms. Al(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form AlO6 octahedra that share corners with four equivalent Ge(1)O5 square pyramids and edges with two equivalent Al(1)O6 octahedra. Ge(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted GeO5 square pyramids that share corners with four equivalent Al(1)O6 octahedra and  an edgeedge with one Ge(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 49-51°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Y(1) and two equivalent Al(1) atoms to form distorted OY2Al2 trigonal pyramids that share corners with four equivalent O(3)Y2AlGe tetrahedra, corners with four equivalent O(4)Y2Ge2 tetrahedra, corners with two equivalent O(1)Y2Al2 trigonal pyramids, edges with four equivalent O(3)Y2AlGe tetrahedra, and  an edgeedge with one O(1)Y2Al2 trigonal pyramid. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Al(1) and one Ge(1) atom. In the third O site, O(3) is bonded to two equivalent Y(1), one Al(1), and one Ge(1) atom to form distorted OY2AlGe tetrahedra that share corners with four equivalent O(4)Y2Ge2 tetrahedra, corners with six equivalent O(3)Y2AlGe tetrahedra, corners with two equivalent O(1)Y2Al2 trigonal pyramids,  an edgeedge with one O(3)Y2AlGe tetrahedra,  an edgeedge with one O(4)Y2Ge2 tetrahedra, and edges with two equivalent O(1)Y2Al2 trigonal pyramids. In the fourth O site, O(4) is bonded to two equivalent Y(1) and two equivalent Ge(1) atoms to form distorted OY2Ge2 tetrahedra that share corners with eight equivalent O(3)Y2AlGe tetrahedra, corners with four equivalent O(1)Y2Al2 trigonal pyramids, edges with two equivalent O(3)Y2AlGe tetrahedra, and edges with two equivalent O(4)Y2Ge2 tetrahedra.
YAlGeO5 crystallizes in the orthorhombic Pbam space group. Y(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), and four equivalent O(3) atoms. There is one shorter (2.30 Å) and one longer (2.39 Å) Y(1)-O(1) bond length. Both Y(1)-O(4) bond lengths are 2.42 Å. There are two shorter (2.36 Å) and two longer (2.51 Å) Y(1)-O(3) bond lengths. Al(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form AlO6 octahedra that share corners with four equivalent Ge(1)O5 square pyramids and edges with two equivalent Al(1)O6 octahedra. Both Al(1)-O(1) bond lengths are 1.90 Å. Both Al(1)-O(2) bond lengths are 1.90 Å. Both Al(1)-O(3) bond lengths are 1.95 Å. Ge(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted GeO5 square pyramids that share corners with four equivalent Al(1)O6 octahedra and  an edgeedge with one Ge(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 49-51°. The Ge(1)-O(2) bond length is 1.78 Å. Both Ge(1)-O(3) bond lengths are 1.85 Å. Both Ge(1)-O(4) bond lengths are 1.93 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Y(1) and two equivalent Al(1) atoms to form distorted OY2Al2 trigonal pyramids that share corners with four equivalent O(3)Y2AlGe tetrahedra, corners with four equivalent O(4)Y2Ge2 tetrahedra, corners with two equivalent O(1)Y2Al2 trigonal pyramids, edges with four equivalent O(3)Y2AlGe tetrahedra, and  an edgeedge with one O(1)Y2Al2 trigonal pyramid. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Al(1) and one Ge(1) atom. In the third O site, O(3) is bonded to two equivalent Y(1), one Al(1), and one Ge(1) atom to form distorted OY2AlGe tetrahedra that share corners with four equivalent O(4)Y2Ge2 tetrahedra, corners with six equivalent O(3)Y2AlGe tetrahedra, corners with two equivalent O(1)Y2Al2 trigonal pyramids,  an edgeedge with one O(3)Y2AlGe tetrahedra,  an edgeedge with one O(4)Y2Ge2 tetrahedra, and edges with two equivalent O(1)Y2Al2 trigonal pyramids. In the fourth O site, O(4) is bonded to two equivalent Y(1) and two equivalent Ge(1) atoms to form distorted OY2Ge2 tetrahedra that share corners with eight equivalent O(3)Y2AlGe tetrahedra, corners with four equivalent O(1)Y2Al2 trigonal pyramids, edges with two equivalent O(3)Y2AlGe tetrahedra, and edges with two equivalent O(4)Y2Ge2 tetrahedra.