Sr4CaMn2(GaO5)2 crystallizes in the monoclinic C2/m space group. Sr(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Ca(1) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form CaO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Ga(1)O4 tetrahedra, and edges with two equivalent Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted MnO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and corners with two equivalent Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 1-41°. Ga(1) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form GaO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra,  an edgeedge with one Ca(1)O6 octahedra, and  an edgeedge with one Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-46°. There are four inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Mn(1) atoms to form a mixture of distorted face, edge, and corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to four equivalent Sr(1) and two equivalent Mn(1) atoms to form a mixture of face, edge, and corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one Ca(1), one Mn(1), and one Ga(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one Ca(1), and two equivalent Ga(1) atoms.
Sr4CaMn2(GaO5)2 crystallizes in the monoclinic C2/m space group. Sr(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The Sr(1)-O(4) bond length is 2.68 Å. There is one shorter (2.54 Å) and one longer (2.68 Å) Sr(1)-O(1) bond length. There is one shorter (2.63 Å) and one longer (2.64 Å) Sr(1)-O(2) bond length. There is one shorter (2.84 Å) and one longer (2.89 Å) Sr(1)-O(3) bond length. Ca(1) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form CaO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Ga(1)O4 tetrahedra, and edges with two equivalent Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. Both Ca(1)-O(4) bond lengths are 2.70 Å. All Ca(1)-O(3) bond lengths are 2.30 Å. Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted MnO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and corners with two equivalent Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 1-41°. Both Mn(1)-O(1) bond lengths are 2.09 Å. Both Mn(1)-O(2) bond lengths are 2.05 Å. Both Mn(1)-O(3) bond lengths are 2.71 Å. Ga(1) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form GaO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra,  an edgeedge with one Ca(1)O6 octahedra, and  an edgeedge with one Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-46°. Both Ga(1)-O(3) bond lengths are 1.87 Å. Both Ga(1)-O(4) bond lengths are 1.95 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Mn(1) atoms to form a mixture of distorted face, edge, and corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to four equivalent Sr(1) and two equivalent Mn(1) atoms to form a mixture of face, edge, and corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one Ca(1), one Mn(1), and one Ga(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one Ca(1), and two equivalent Ga(1) atoms.