Sr4CaMn2Ga2O11 crystallizes in the monoclinic C2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), and two equivalent O(3) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), one O(5), two equivalent O(3), and two equivalent O(7) atoms. Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(7) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with four equivalent Mn(2)O6 octahedra and corners with two equivalent Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 0-19°. In the second Mn site, Mn(2) is bonded to one O(4), one O(5), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share 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 0-19°. Ga(1) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form GaO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra, and  a cornercorner with one Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-47°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one Mn(1), and one Ga(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one Mn(2), and one Ga(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Mn(1), and one Mn(2) atom. In the fourth O site, O(4) is bonded to two equivalent Sr(1), two equivalent Sr(2), one Mn(1), and one Mn(2) atom to form distorted OSr4Mn2 octahedra that share corners with two equivalent O(5)Sr4Mn2 octahedra, corners with two equivalent O(6)Sr2Ga2 tetrahedra, and edges with two equivalent O(5)Sr4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to two equivalent Sr(1), two equivalent Sr(2), one Mn(1), and one Mn(2) atom to form distorted OSr4Mn2 octahedra that share corners with two equivalent O(4)Sr4Mn2 octahedra, corners with two equivalent O(6)Sr2Ga2 tetrahedra, and edges with two equivalent O(4)Sr4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded to two equivalent Sr(1) and two equivalent Ga(1) atoms to form corner-sharing OSr2Ga2 tetrahedra. The corner-sharing octahedral tilt angles range from 53-64°. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Sr(2), one Ca(1), and one Ga(1) atom.
Sr4CaMn2Ga2O11 crystallizes in the monoclinic C2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), and two equivalent O(3) atoms. The Sr(1)-O(1) bond length is 2.64 Å. The Sr(1)-O(2) bond length is 2.75 Å. The Sr(1)-O(4) bond length is 2.69 Å. The Sr(1)-O(5) bond length is 2.73 Å. The Sr(1)-O(6) bond length is 2.50 Å. There is one shorter (2.62 Å) and one longer (3.13 Å) Sr(1)-O(3) bond length. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), one O(5), two equivalent O(3), and two equivalent O(7) atoms. The Sr(2)-O(1) bond length is 2.88 Å. The Sr(2)-O(2) bond length is 2.91 Å. The Sr(2)-O(4) bond length is 2.53 Å. The Sr(2)-O(5) bond length is 2.50 Å. There is one shorter (2.54 Å) and one longer (2.86 Å) Sr(2)-O(3) bond length. There is one shorter (2.63 Å) and one longer (2.72 Å) Sr(2)-O(7) bond length. Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(7) atoms. Both Ca(1)-O(1) bond lengths are 2.29 Å. Both Ca(1)-O(2) bond lengths are 2.40 Å. Both Ca(1)-O(7) bond lengths are 2.22 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with four equivalent Mn(2)O6 octahedra and corners with two equivalent Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 0-19°. The Mn(1)-O(4) bond length is 1.99 Å. The Mn(1)-O(5) bond length is 1.98 Å. Both Mn(1)-O(1) bond lengths are 2.26 Å. Both Mn(1)-O(3) bond lengths are 2.17 Å. In the second Mn site, Mn(2) is bonded to one O(4), one O(5), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share 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 0-19°. The Mn(2)-O(4) bond length is 2.50 Å. The Mn(2)-O(5) bond length is 2.53 Å. Both Mn(2)-O(2) bond lengths are 2.10 Å. Both Mn(2)-O(3) bond lengths are 1.95 Å. Ga(1) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form GaO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra, and  a cornercorner with one Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-47°. The Ga(1)-O(1) bond length is 1.90 Å. The Ga(1)-O(2) bond length is 1.95 Å. The Ga(1)-O(6) bond length is 1.87 Å. The Ga(1)-O(7) bond length is 1.81 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one Mn(1), and one Ga(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one Mn(2), and one Ga(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Mn(1), and one Mn(2) atom. In the fourth O site, O(4) is bonded to two equivalent Sr(1), two equivalent Sr(2), one Mn(1), and one Mn(2) atom to form distorted OSr4Mn2 octahedra that share corners with two equivalent O(5)Sr4Mn2 octahedra, corners with two equivalent O(6)Sr2Ga2 tetrahedra, and edges with two equivalent O(5)Sr4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to two equivalent Sr(1), two equivalent Sr(2), one Mn(1), and one Mn(2) atom to form distorted OSr4Mn2 octahedra that share corners with two equivalent O(4)Sr4Mn2 octahedra, corners with two equivalent O(6)Sr2Ga2 tetrahedra, and edges with two equivalent O(4)Sr4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded to two equivalent Sr(1) and two equivalent Ga(1) atoms to form corner-sharing OSr2Ga2 tetrahedra. The corner-sharing octahedral tilt angles range from 53-64°. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Sr(2), one Ca(1), and one Ga(1) atom.