SrCa3(SnO3)4 crystallizes in the monoclinic Pm space group. Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), two equivalent O(5), two equivalent O(6), and two equivalent O(8) 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(2), two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form corner-sharing SnO6 octahedra. The corner-sharing octahedral tilt angles range from 29-34°. In the second Sn site, Sn(2) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form corner-sharing SnO6 octahedra. The corner-sharing octahedral tilt angles range from 28-35°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Ca(1), and two equivalent Sn(1) atoms to form distorted OSrCaSn2 tetrahedra that share corners with two equivalent O(3)Ca2Sn2 tetrahedra and corners with two equivalent O(2)SrCaSn2 tetrahedra. In the second O site, O(2) is bonded to one Sr(1), one Ca(1), and two equivalent Sn(2) atoms to form distorted OSrCaSn2 tetrahedra that share corners with two equivalent O(4)Ca2Sn2 tetrahedra and corners with two equivalent O(1)SrCaSn2 tetrahedra. In the third O site, O(3) is bonded to one Ca(2), one Ca(3), and two equivalent Sn(1) atoms to form distorted OCa2Sn2 tetrahedra that share corners with two equivalent O(4)Ca2Sn2 tetrahedra and corners with two equivalent O(1)SrCaSn2 tetrahedra. In the fourth O site, O(4) is bonded to one Ca(2), one Ca(3), and two equivalent Sn(2) atoms to form distorted OCa2Sn2 tetrahedra that share corners with two equivalent O(3)Ca2Sn2 tetrahedra and corners with two equivalent O(2)SrCaSn2 tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Sr(1), one Ca(1), one Ca(3), one Sn(1), and one Sn(2) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Sn(1), and one Sn(2) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), one Sn(1), and one Sn(2) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Sr(1), one Ca(2), one Ca(3), one Sn(1), and one Sn(2) atom.
SrCa3(SnO3)4 crystallizes in the monoclinic Pm space group. Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), two equivalent O(5), two equivalent O(6), and two equivalent O(8) atoms. The Sr(1)-O(1) bond length is 2.59 Å. The Sr(1)-O(2) bond length is 2.47 Å. Both Sr(1)-O(5) bond lengths are 2.75 Å. Both Sr(1)-O(6) bond lengths are 2.46 Å. Both Sr(1)-O(8) bond lengths are 2.87 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(2), two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms. The Ca(1)-O(1) bond length is 2.35 Å. The Ca(1)-O(2) bond length is 2.42 Å. Both Ca(1)-O(5) bond lengths are 2.39 Å. Both Ca(1)-O(6) bond lengths are 2.68 Å. Both Ca(1)-O(7) bond lengths are 2.88 Å. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. The Ca(2)-O(3) bond length is 2.45 Å. The Ca(2)-O(4) bond length is 2.36 Å. Both Ca(2)-O(6) bond lengths are 2.81 Å. Both Ca(2)-O(7) bond lengths are 2.66 Å. Both Ca(2)-O(8) bond lengths are 2.39 Å. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. The Ca(3)-O(3) bond length is 2.35 Å. The Ca(3)-O(4) bond length is 2.45 Å. Both Ca(3)-O(5) bond lengths are 2.82 Å. Both Ca(3)-O(7) bond lengths are 2.39 Å. Both Ca(3)-O(8) bond lengths are 2.70 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form corner-sharing SnO6 octahedra. The corner-sharing octahedral tilt angles range from 29-34°. The Sn(1)-O(1) bond length is 2.11 Å. The Sn(1)-O(3) bond length is 2.09 Å. The Sn(1)-O(5) bond length is 2.10 Å. The Sn(1)-O(6) bond length is 2.08 Å. The Sn(1)-O(7) bond length is 2.10 Å. The Sn(1)-O(8) bond length is 2.10 Å. In the second Sn site, Sn(2) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form corner-sharing SnO6 octahedra. The corner-sharing octahedral tilt angles range from 28-35°. The Sn(2)-O(2) bond length is 2.10 Å. The Sn(2)-O(4) bond length is 2.09 Å. The Sn(2)-O(5) bond length is 2.10 Å. The Sn(2)-O(6) bond length is 2.09 Å. The Sn(2)-O(7) bond length is 2.10 Å. The Sn(2)-O(8) bond length is 2.10 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Ca(1), and two equivalent Sn(1) atoms to form distorted OSrCaSn2 tetrahedra that share corners with two equivalent O(3)Ca2Sn2 tetrahedra and corners with two equivalent O(2)SrCaSn2 tetrahedra. In the second O site, O(2) is bonded to one Sr(1), one Ca(1), and two equivalent Sn(2) atoms to form distorted OSrCaSn2 tetrahedra that share corners with two equivalent O(4)Ca2Sn2 tetrahedra and corners with two equivalent O(1)SrCaSn2 tetrahedra. In the third O site, O(3) is bonded to one Ca(2), one Ca(3), and two equivalent Sn(1) atoms to form distorted OCa2Sn2 tetrahedra that share corners with two equivalent O(4)Ca2Sn2 tetrahedra and corners with two equivalent O(1)SrCaSn2 tetrahedra. In the fourth O site, O(4) is bonded to one Ca(2), one Ca(3), and two equivalent Sn(2) atoms to form distorted OCa2Sn2 tetrahedra that share corners with two equivalent O(3)Ca2Sn2 tetrahedra and corners with two equivalent O(2)SrCaSn2 tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Sr(1), one Ca(1), one Ca(3), one Sn(1), and one Sn(2) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Sn(1), and one Sn(2) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), one Sn(1), and one Sn(2) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Sr(1), one Ca(2), one Ca(3), one Sn(1), and one Sn(2) atom.