BaGa2Ge2O8 crystallizes in the monoclinic P2_1/c space group. Ba(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted BaO7 hexagonal pyramids that share corners with two equivalent Ga(2)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with three equivalent Ga(1)O4 tetrahedra, corners with three equivalent Ge(1)O4 tetrahedra,  an edgeedge with one Ga(2)O4 tetrahedra, and  an edgeedge with one Ge(2)O4 tetrahedra. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form GaO4 tetrahedra that share corners with three equivalent Ba(1)O7 hexagonal pyramids,  a cornercorner with one Ge(1)O4 tetrahedra, and corners with three equivalent Ge(2)O4 tetrahedra. In the second Ga site, Ga(2) is bonded to one O(1), one O(3), one O(5), and one O(8) atom to form GaO4 tetrahedra that share corners with two equivalent Ba(1)O7 hexagonal pyramids,  a cornercorner with one Ge(2)O4 tetrahedra, corners with three equivalent Ge(1)O4 tetrahedra, and  an edgeedge with one Ba(1)O7 hexagonal pyramid. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form GeO4 tetrahedra that share corners with three equivalent Ba(1)O7 hexagonal pyramids,  a cornercorner with one Ga(1)O4 tetrahedra, and corners with three equivalent Ga(2)O4 tetrahedra. In the second Ge site, Ge(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form GeO4 tetrahedra that share corners with two equivalent Ba(1)O7 hexagonal pyramids,  a cornercorner with one Ga(2)O4 tetrahedra, corners with three equivalent Ga(1)O4 tetrahedra, and  an edgeedge with one Ba(1)O7 hexagonal pyramid. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), one Ga(1), and one Ge(2) atom. In the second O site, O(5) is bonded in a distorted trigonal planar geometry to one Ba(1), one Ga(2), and one Ge(1) atom. In the third O site, O(6) is bonded in a distorted trigonal planar geometry to one Ba(1), one Ga(1), and one Ge(2) atom. In the fourth O site, O(7) is bonded in a bent 120 degrees geometry to one Ga(1) and one Ge(1) atom. In the fifth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ba(1), one Ga(2), and one Ge(2) atom. In the sixth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ga(2), and one Ge(1) atom. In the seventh O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ga(1), and one Ge(2) atom. In the eighth O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ga(2), and one Ge(1) atom.
BaGa2Ge2O8 crystallizes in the monoclinic P2_1/c space group. Ba(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted BaO7 hexagonal pyramids that share corners with two equivalent Ga(2)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, corners with three equivalent Ga(1)O4 tetrahedra, corners with three equivalent Ge(1)O4 tetrahedra,  an edgeedge with one Ga(2)O4 tetrahedra, and  an edgeedge with one Ge(2)O4 tetrahedra. The Ba(1)-O(1) bond length is 2.78 Å. The Ba(1)-O(2) bond length is 2.82 Å. The Ba(1)-O(3) bond length is 2.79 Å. The Ba(1)-O(4) bond length is 2.78 Å. The Ba(1)-O(5) bond length is 2.74 Å. The Ba(1)-O(6) bond length is 2.75 Å. The Ba(1)-O(8) bond length is 2.76 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form GaO4 tetrahedra that share corners with three equivalent Ba(1)O7 hexagonal pyramids,  a cornercorner with one Ge(1)O4 tetrahedra, and corners with three equivalent Ge(2)O4 tetrahedra. The Ga(1)-O(2) bond length is 1.84 Å. The Ga(1)-O(4) bond length is 1.84 Å. The Ga(1)-O(6) bond length is 1.84 Å. The Ga(1)-O(7) bond length is 1.82 Å. In the second Ga site, Ga(2) is bonded to one O(1), one O(3), one O(5), and one O(8) atom to form GaO4 tetrahedra that share corners with two equivalent Ba(1)O7 hexagonal pyramids,  a cornercorner with one Ge(2)O4 tetrahedra, corners with three equivalent Ge(1)O4 tetrahedra, and  an edgeedge with one Ba(1)O7 hexagonal pyramid. The Ga(2)-O(1) bond length is 1.83 Å. The Ga(2)-O(3) bond length is 1.86 Å. The Ga(2)-O(5) bond length is 1.82 Å. The Ga(2)-O(8) bond length is 1.84 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form GeO4 tetrahedra that share corners with three equivalent Ba(1)O7 hexagonal pyramids,  a cornercorner with one Ga(1)O4 tetrahedra, and corners with three equivalent Ga(2)O4 tetrahedra. The Ge(1)-O(1) bond length is 1.76 Å. The Ge(1)-O(3) bond length is 1.76 Å. The Ge(1)-O(5) bond length is 1.75 Å. The Ge(1)-O(7) bond length is 1.74 Å. In the second Ge site, Ge(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form GeO4 tetrahedra that share corners with two equivalent Ba(1)O7 hexagonal pyramids,  a cornercorner with one Ga(2)O4 tetrahedra, corners with three equivalent Ga(1)O4 tetrahedra, and  an edgeedge with one Ba(1)O7 hexagonal pyramid. The Ge(2)-O(2) bond length is 1.75 Å. The Ge(2)-O(4) bond length is 1.76 Å. The Ge(2)-O(6) bond length is 1.74 Å. The Ge(2)-O(8) bond length is 1.76 Å. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), one Ga(1), and one Ge(2) atom. In the second O site, O(5) is bonded in a distorted trigonal planar geometry to one Ba(1), one Ga(2), and one Ge(1) atom. In the third O site, O(6) is bonded in a distorted trigonal planar geometry to one Ba(1), one Ga(1), and one Ge(2) atom. In the fourth O site, O(7) is bonded in a bent 120 degrees geometry to one Ga(1) and one Ge(1) atom. In the fifth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ba(1), one Ga(2), and one Ge(2) atom. In the sixth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ga(2), and one Ge(1) atom. In the seventh O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ga(1), and one Ge(2) atom. In the eighth O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ga(2), and one Ge(1) atom.