SrCa5Mn4(GaO8)2 crystallizes in the monoclinic Pm space group. Sr(1) is bonded in a 12-coordinate geometry to two equivalent O(10), two equivalent O(3), two equivalent O(4), two equivalent O(7), two equivalent O(8), and two equivalent O(9) atoms. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(6), one O(9), and two equivalent O(5) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(3), one O(4), one O(5), one O(9), and two equivalent O(6) atoms. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(7), one O(8), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(10), one O(3), one O(4), one O(5), one O(7), and one O(9) atom to form MnO6 octahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, and  a cornercorner with one Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-20°. In the second Mn site, Mn(2) is bonded to one O(10), one O(3), one O(4), one O(6), one O(8), and one O(9) atom to form MnO6 octahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and  a cornercorner with one Ga(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-25°. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(1), one O(2), and two equivalent O(5) atoms to form GaO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with two equivalent Ga(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. In the second Ga site, Ga(2) is bonded to one O(1), one O(2), and two equivalent O(6) atoms to form GaO4 tetrahedra that share corners with two equivalent Mn(2)O6 octahedra and corners with two equivalent Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1), one Ga(1), and one Ga(2) atom to form distorted OCa2Ga2 tetrahedra that share corners with two equivalent O(3)SrCa3Mn2 octahedra, corners with two equivalent O(4)SrCa3Mn2 octahedra, and corners with two equivalent O(2)Ca2Ga2 tetrahedra. The corner-sharing octahedral tilt angles range from 21-50°. In the second O site, O(2) is bonded to two equivalent Ca(2), one Ga(1), and one Ga(2) atom to form distorted OCa2Ga2 tetrahedra that share corners with two equivalent O(3)SrCa3Mn2 octahedra, corners with two equivalent O(4)SrCa3Mn2 octahedra, and corners with two equivalent O(1)Ca2Ga2 tetrahedra. The corner-sharing octahedral tilt angles range from 21-50°. In the third O site, O(3) is bonded to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(1), and one Mn(2) atom to form distorted OSrCa3Mn2 octahedra that share corners with two equivalent O(4)SrCa3Mn2 octahedra,  a cornercorner with one O(1)Ca2Ga2 tetrahedra,  a cornercorner with one O(2)Ca2Ga2 tetrahedra,  an edgeedge with one O(3)SrCa3Mn2 octahedra, and faces with two equivalent O(4)SrCa3Mn2 octahedra. The corner-sharing octahedral tilt angles range from 62-65°. In the fourth O site, O(4) is bonded to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(1), and one Mn(2) atom to form distorted OSrCa3Mn2 octahedra that share corners with two equivalent O(3)SrCa3Mn2 octahedra,  a cornercorner with one O(1)Ca2Ga2 tetrahedra,  a cornercorner with one O(2)Ca2Ga2 tetrahedra,  an edgeedge with one O(4)SrCa3Mn2 octahedra, and faces with two equivalent O(3)SrCa3Mn2 octahedra. The corner-sharing octahedral tilt angles range from 62-65°. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), one Mn(1), and one Ga(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Mn(2), and one Ga(2) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Sr(1), one Ca(3), and two equivalent Mn(1) atoms. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one Ca(3), and two equivalent Mn(2) atoms. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Mn(1), and one Mn(2) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Mn(1), and one Mn(2) atom.
SrCa5Mn4(GaO8)2 crystallizes in the monoclinic Pm space group. Sr(1) is bonded in a 12-coordinate geometry to two equivalent O(10), two equivalent O(3), two equivalent O(4), two equivalent O(7), two equivalent O(8), and two equivalent O(9) atoms. Both Sr(1)-O(10) bond lengths are 2.93 Å. Both Sr(1)-O(3) bond lengths are 2.62 Å. Both Sr(1)-O(4) bond lengths are 2.62 Å. There is one shorter (2.50 Å) and one longer (3.14 Å) Sr(1)-O(7) bond length. There is one shorter (2.75 Å) and one longer (2.79 Å) Sr(1)-O(8) bond length. Both Sr(1)-O(9) bond lengths are 3.03 Å. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(6), one O(9), and two equivalent O(5) atoms. The Ca(1)-O(1) bond length is 2.36 Å. The Ca(1)-O(10) bond length is 2.42 Å. The Ca(1)-O(3) bond length is 2.54 Å. The Ca(1)-O(4) bond length is 2.45 Å. The Ca(1)-O(6) bond length is 2.32 Å. The Ca(1)-O(9) bond length is 2.41 Å. There is one shorter (2.61 Å) and one longer (2.97 Å) Ca(1)-O(5) bond length. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(3), one O(4), one O(5), one O(9), and two equivalent O(6) atoms. The Ca(2)-O(10) bond length is 2.40 Å. The Ca(2)-O(2) bond length is 2.34 Å. The Ca(2)-O(3) bond length is 2.48 Å. The Ca(2)-O(4) bond length is 2.64 Å. The Ca(2)-O(5) bond length is 2.31 Å. The Ca(2)-O(9) bond length is 2.40 Å. There is one shorter (2.60 Å) and one longer (2.97 Å) Ca(2)-O(6) bond length. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(7), one O(8), two equivalent O(3), and two equivalent O(4) atoms. The Ca(3)-O(7) bond length is 2.63 Å. The Ca(3)-O(8) bond length is 2.43 Å. Both Ca(3)-O(3) bond lengths are 2.53 Å. Both Ca(3)-O(4) bond lengths are 2.55 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(10), one O(3), one O(4), one O(5), one O(7), and one O(9) atom to form MnO6 octahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, and  a cornercorner with one Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-20°. The Mn(1)-O(10) bond length is 1.97 Å. The Mn(1)-O(3) bond length is 2.00 Å. The Mn(1)-O(4) bond length is 2.00 Å. The Mn(1)-O(5) bond length is 2.11 Å. The Mn(1)-O(7) bond length is 1.94 Å. The Mn(1)-O(9) bond length is 1.96 Å. In the second Mn site, Mn(2) is bonded to one O(10), one O(3), one O(4), one O(6), one O(8), and one O(9) atom to form MnO6 octahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and  a cornercorner with one Ga(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-25°. The Mn(2)-O(10) bond length is 1.95 Å. The Mn(2)-O(3) bond length is 2.00 Å. The Mn(2)-O(4) bond length is 2.00 Å. The Mn(2)-O(6) bond length is 2.11 Å. The Mn(2)-O(8) bond length is 1.96 Å. The Mn(2)-O(9) bond length is 1.97 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(1), one O(2), and two equivalent O(5) atoms to form GaO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with two equivalent Ga(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. The Ga(1)-O(1) bond length is 1.92 Å. The Ga(1)-O(2) bond length is 1.90 Å. Both Ga(1)-O(5) bond lengths are 1.85 Å. In the second Ga site, Ga(2) is bonded to one O(1), one O(2), and two equivalent O(6) atoms to form GaO4 tetrahedra that share corners with two equivalent Mn(2)O6 octahedra and corners with two equivalent Ga(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. The Ga(2)-O(1) bond length is 1.90 Å. The Ga(2)-O(2) bond length is 1.92 Å. Both Ga(2)-O(6) bond lengths are 1.85 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1), one Ga(1), and one Ga(2) atom to form distorted OCa2Ga2 tetrahedra that share corners with two equivalent O(3)SrCa3Mn2 octahedra, corners with two equivalent O(4)SrCa3Mn2 octahedra, and corners with two equivalent O(2)Ca2Ga2 tetrahedra. The corner-sharing octahedral tilt angles range from 21-50°. In the second O site, O(2) is bonded to two equivalent Ca(2), one Ga(1), and one Ga(2) atom to form distorted OCa2Ga2 tetrahedra that share corners with two equivalent O(3)SrCa3Mn2 octahedra, corners with two equivalent O(4)SrCa3Mn2 octahedra, and corners with two equivalent O(1)Ca2Ga2 tetrahedra. The corner-sharing octahedral tilt angles range from 21-50°. In the third O site, O(3) is bonded to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(1), and one Mn(2) atom to form distorted OSrCa3Mn2 octahedra that share corners with two equivalent O(4)SrCa3Mn2 octahedra,  a cornercorner with one O(1)Ca2Ga2 tetrahedra,  a cornercorner with one O(2)Ca2Ga2 tetrahedra,  an edgeedge with one O(3)SrCa3Mn2 octahedra, and faces with two equivalent O(4)SrCa3Mn2 octahedra. The corner-sharing octahedral tilt angles range from 62-65°. In the fourth O site, O(4) is bonded to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(1), and one Mn(2) atom to form distorted OSrCa3Mn2 octahedra that share corners with two equivalent O(3)SrCa3Mn2 octahedra,  a cornercorner with one O(1)Ca2Ga2 tetrahedra,  a cornercorner with one O(2)Ca2Ga2 tetrahedra,  an edgeedge with one O(4)SrCa3Mn2 octahedra, and faces with two equivalent O(3)SrCa3Mn2 octahedra. The corner-sharing octahedral tilt angles range from 62-65°. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), one Mn(1), and one Ga(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Mn(2), and one Ga(2) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Sr(1), one Ca(3), and two equivalent Mn(1) atoms. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one Ca(3), and two equivalent Mn(2) atoms. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Mn(1), and one Mn(2) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Mn(1), and one Mn(2) atom.