CaGa4O7 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form CaO5 trigonal bipyramids that share corners with four equivalent Ga(2)O4 tetrahedra and corners with six equivalent Ga(1)O4 tetrahedra. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(2), one O(4), and two equivalent O(3) atoms to form GaO4 tetrahedra that share corners with two equivalent Ga(1)O4 tetrahedra, corners with three equivalent Ga(2)O4 tetrahedra, and corners with three equivalent Ca(1)O5 trigonal bipyramids. In the second Ga site, Ga(2) is bonded to one O(1), one O(2), and two equivalent O(4) atoms to form GaO4 tetrahedra that share corners with three equivalent Ga(1)O4 tetrahedra, corners with three equivalent Ga(2)O4 tetrahedra, and corners with two equivalent Ca(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Ga(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ca(1), one Ga(1), and one Ga(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Ga(1) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ga(1) and two equivalent Ga(2) atoms.
CaGa4O7 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form CaO5 trigonal bipyramids that share corners with four equivalent Ga(2)O4 tetrahedra and corners with six equivalent Ga(1)O4 tetrahedra. The Ca(1)-O(1) bond length is 2.35 Å. Both Ca(1)-O(2) bond lengths are 2.33 Å. Both Ca(1)-O(3) bond lengths are 2.31 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(2), one O(4), and two equivalent O(3) atoms to form GaO4 tetrahedra that share corners with two equivalent Ga(1)O4 tetrahedra, corners with three equivalent Ga(2)O4 tetrahedra, and corners with three equivalent Ca(1)O5 trigonal bipyramids. The Ga(1)-O(2) bond length is 1.83 Å. The Ga(1)-O(4) bond length is 1.88 Å. There is one shorter (1.84 Å) and one longer (1.85 Å) Ga(1)-O(3) bond length. In the second Ga site, Ga(2) is bonded to one O(1), one O(2), and two equivalent O(4) atoms to form GaO4 tetrahedra that share corners with three equivalent Ga(1)O4 tetrahedra, corners with three equivalent Ga(2)O4 tetrahedra, and corners with two equivalent Ca(1)O5 trigonal bipyramids. The Ga(2)-O(1) bond length is 1.84 Å. The Ga(2)-O(2) bond length is 1.81 Å. There is one shorter (1.87 Å) and one longer (1.88 Å) Ga(2)-O(4) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Ga(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ca(1), one Ga(1), and one Ga(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Ga(1) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ga(1) and two equivalent Ga(2) atoms.