Ba3GeO5 crystallizes in the trigonal R3m space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a distorted hexagonal planar geometry to one O(3), one O(5), one O(7), one O(9), and two equivalent O(4) atoms. In the second Ba site, Ba(2) is bonded to one O(2), one O(5), one O(6), one O(8), and two equivalent O(3) atoms to form distorted BaO6 octahedra that share corners with two equivalent Ba(2)O6 octahedra,  a cornercorner with one Ba(3)O6 pentagonal pyramid,  a cornercorner with one Ge(2)O4 tetrahedra,  a cornercorner with one Ge(3)O4 tetrahedra, corners with two equivalent Ge(1)O4 tetrahedra, edges with two equivalent Ba(3)O6 pentagonal pyramids, and faces with two equivalent Ba(2)O6 octahedra. The corner-sharing octahedral tilt angles are 81°. In the third Ba site, Ba(3) is bonded to one O(1), one O(4), one O(6), one O(7), and two equivalent O(2) atoms to form distorted BaO6 pentagonal pyramids that share  a cornercorner with one Ba(2)O6 octahedra, corners with two equivalent Ba(3)O6 pentagonal pyramids,  a cornercorner with one Ge(1)O4 tetrahedra,  a cornercorner with one Ge(2)O4 tetrahedra, corners with two equivalent Ge(3)O4 tetrahedra, edges with two equivalent Ba(2)O6 octahedra, and faces with two equivalent Ba(3)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 1°. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1) and three equivalent O(3) atoms to form GeO4 tetrahedra that share corners with six equivalent Ba(2)O6 octahedra and corners with three equivalent Ba(3)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 54°. In the second Ge site, Ge(2) is bonded to one O(8) and three equivalent O(4) atoms to form GeO4 tetrahedra that share corners with three equivalent Ba(2)O6 octahedra and corners with three equivalent Ba(3)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 62°. In the third Ge site, Ge(3) is bonded to one O(9) and three equivalent O(2) atoms to form GeO4 tetrahedra that share corners with three equivalent Ba(2)O6 octahedra and corners with six equivalent Ba(3)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 55°. There are nine inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ba(3) and one Ge(1) atom to form distorted corner-sharing OBa3Ge tetrahedra. The corner-sharing octahedral tilt angles range from 11-63°. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ba(2), two equivalent Ba(3), and one Ge(3) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ba(1), two equivalent Ba(2), and one Ge(1) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Ba(3), two equivalent Ba(1), and one Ge(2) atom. In the fifth O site, O(5) is bonded to three equivalent Ba(1) and three equivalent Ba(2) atoms to form OBa6 octahedra that share corners with three equivalent O(7)Ba6 octahedra, corners with three equivalent O(8)Ba3Ge tetrahedra, and  a faceface with one O(6)Ba6 octahedra. The corner-sharing octahedral tilt angles are 2°. In the sixth O site, O(6) is bonded to three equivalent Ba(2) and three equivalent Ba(3) atoms to form OBa6 octahedra that share corners with three equivalent O(1)Ba3Ge tetrahedra, corners with three equivalent O(8)Ba3Ge tetrahedra,  a faceface with one O(5)Ba6 octahedra, and  a faceface with one O(7)Ba6 octahedra. In the seventh O site, O(7) is bonded to three equivalent Ba(1) and three equivalent Ba(3) atoms to form OBa6 octahedra that share corners with three equivalent O(5)Ba6 octahedra, corners with three equivalent O(1)Ba3Ge tetrahedra, and  a faceface with one O(6)Ba6 octahedra. The corner-sharing octahedral tilt angles are 2°. In the eighth O site, O(8) is bonded to three equivalent Ba(2) and one Ge(2) atom to form distorted corner-sharing OBa3Ge tetrahedra. The corner-sharing octahedral tilt angles range from 8-65°. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to three equivalent Ba(1) and one Ge(3) atom.
Ba3GeO5 crystallizes in the trigonal R3m space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a distorted hexagonal planar geometry to one O(3), one O(5), one O(7), one O(9), and two equivalent O(4) atoms. The Ba(1)-O(3) bond length is 2.78 Å. The Ba(1)-O(5) bond length is 2.83 Å. The Ba(1)-O(7) bond length is 2.74 Å. The Ba(1)-O(9) bond length is 2.72 Å. Both Ba(1)-O(4) bond lengths are 2.76 Å. In the second Ba site, Ba(2) is bonded to one O(2), one O(5), one O(6), one O(8), and two equivalent O(3) atoms to form distorted BaO6 octahedra that share corners with two equivalent Ba(2)O6 octahedra,  a cornercorner with one Ba(3)O6 pentagonal pyramid,  a cornercorner with one Ge(2)O4 tetrahedra,  a cornercorner with one Ge(3)O4 tetrahedra, corners with two equivalent Ge(1)O4 tetrahedra, edges with two equivalent Ba(3)O6 pentagonal pyramids, and faces with two equivalent Ba(2)O6 octahedra. The corner-sharing octahedral tilt angles are 81°. The Ba(2)-O(2) bond length is 2.77 Å. The Ba(2)-O(5) bond length is 2.71 Å. The Ba(2)-O(6) bond length is 2.72 Å. The Ba(2)-O(8) bond length is 2.81 Å. Both Ba(2)-O(3) bond lengths are 2.71 Å. In the third Ba site, Ba(3) is bonded to one O(1), one O(4), one O(6), one O(7), and two equivalent O(2) atoms to form distorted BaO6 pentagonal pyramids that share  a cornercorner with one Ba(2)O6 octahedra, corners with two equivalent Ba(3)O6 pentagonal pyramids,  a cornercorner with one Ge(1)O4 tetrahedra,  a cornercorner with one Ge(2)O4 tetrahedra, corners with two equivalent Ge(3)O4 tetrahedra, edges with two equivalent Ba(2)O6 octahedra, and faces with two equivalent Ba(3)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 1°. The Ba(3)-O(1) bond length is 2.78 Å. The Ba(3)-O(4) bond length is 2.76 Å. The Ba(3)-O(6) bond length is 2.70 Å. The Ba(3)-O(7) bond length is 2.78 Å. Both Ba(3)-O(2) bond lengths are 2.72 Å. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1) and three equivalent O(3) atoms to form GeO4 tetrahedra that share corners with six equivalent Ba(2)O6 octahedra and corners with three equivalent Ba(3)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 54°. The Ge(1)-O(1) bond length is 1.80 Å. All Ge(1)-O(3) bond lengths are 1.79 Å. In the second Ge site, Ge(2) is bonded to one O(8) and three equivalent O(4) atoms to form GeO4 tetrahedra that share corners with three equivalent Ba(2)O6 octahedra and corners with three equivalent Ba(3)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 62°. The Ge(2)-O(8) bond length is 1.80 Å. All Ge(2)-O(4) bond lengths are 1.79 Å. In the third Ge site, Ge(3) is bonded to one O(9) and three equivalent O(2) atoms to form GeO4 tetrahedra that share corners with three equivalent Ba(2)O6 octahedra and corners with six equivalent Ba(3)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 55°. The Ge(3)-O(9) bond length is 1.78 Å. All Ge(3)-O(2) bond lengths are 1.79 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ba(3) and one Ge(1) atom to form distorted corner-sharing OBa3Ge tetrahedra. The corner-sharing octahedral tilt angles range from 11-63°. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ba(2), two equivalent Ba(3), and one Ge(3) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ba(1), two equivalent Ba(2), and one Ge(1) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Ba(3), two equivalent Ba(1), and one Ge(2) atom. In the fifth O site, O(5) is bonded to three equivalent Ba(1) and three equivalent Ba(2) atoms to form OBa6 octahedra that share corners with three equivalent O(7)Ba6 octahedra, corners with three equivalent O(8)Ba3Ge tetrahedra, and  a faceface with one O(6)Ba6 octahedra. The corner-sharing octahedral tilt angles are 2°. In the sixth O site, O(6) is bonded to three equivalent Ba(2) and three equivalent Ba(3) atoms to form OBa6 octahedra that share corners with three equivalent O(1)Ba3Ge tetrahedra, corners with three equivalent O(8)Ba3Ge tetrahedra,  a faceface with one O(5)Ba6 octahedra, and  a faceface with one O(7)Ba6 octahedra. In the seventh O site, O(7) is bonded to three equivalent Ba(1) and three equivalent Ba(3) atoms to form OBa6 octahedra that share corners with three equivalent O(5)Ba6 octahedra, corners with three equivalent O(1)Ba3Ge tetrahedra, and  a faceface with one O(6)Ba6 octahedra. The corner-sharing octahedral tilt angles are 2°. In the eighth O site, O(8) is bonded to three equivalent Ba(2) and one Ge(2) atom to form distorted corner-sharing OBa3Ge tetrahedra. The corner-sharing octahedral tilt angles range from 8-65°. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to three equivalent Ba(1) and one Ge(3) atom.