Ca(SnO2)2 is Spinel-like structured and crystallizes in the monoclinic Cm space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(13), one O(3), and two equivalent O(1) atoms to form CaO4 tetrahedra that share  a cornercorner with one Ca(6)O6 octahedra, corners with two equivalent Ca(3)O6 octahedra, corners with two equivalent Sn(6)O6 octahedra, and corners with four equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-66°. In the second Ca site, Ca(2) is bonded to one O(5), one O(9), two equivalent O(4), and two equivalent O(7) atoms to form distorted CaO6 octahedra that share corners with three equivalent Sn(2)O4 tetrahedra, corners with three equivalent Sn(7)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Ca(5)O6 octahedra, edges with two equivalent Sn(1)O6 octahedra, and edges with two equivalent Sn(4)O6 octahedra. In the third Ca site, Ca(3) is bonded to one O(2), one O(8), two equivalent O(1), and two equivalent O(7) atoms to form distorted CaO6 octahedra that share  a cornercorner with one Sn(2)O4 tetrahedra, corners with two equivalent Ca(1)O4 tetrahedra, corners with two equivalent Sn(7)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra, and edges with four equivalent Sn(1)O6 octahedra. In the fourth Ca site, Ca(4) is bonded to one O(11), one O(15), two equivalent O(10), and two equivalent O(12) atoms to form distorted CaO6 octahedra that share corners with three equivalent Sn(5)O4 tetrahedra, corners with three equivalent Sn(8)O4 tetrahedra,  an edgeedge with one Ca(5)O6 octahedra,  an edgeedge with one Ca(6)O6 octahedra, edges with two equivalent Sn(4)O6 octahedra, and edges with two equivalent Sn(6)O6 octahedra. In the fifth Ca site, Ca(5) is bonded to one O(14), one O(6), two equivalent O(12), and two equivalent O(4) atoms to form distorted CaO6 octahedra that share  a cornercorner with one Sn(5)O4 tetrahedra,  a cornercorner with one Sn(7)O4 tetrahedra, corners with two equivalent Sn(2)O4 tetrahedra, corners with two equivalent Sn(8)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra,  an edgeedge with one Ca(4)O6 octahedra, and edges with four equivalent Sn(4)O6 octahedra. In the sixth Ca site, Ca(6) is bonded to one O(13), one O(18), two equivalent O(10), and two equivalent O(17) atoms to form CaO6 octahedra that share  a cornercorner with one Ca(1)O4 tetrahedra,  a cornercorner with one Sn(8)O4 tetrahedra, corners with two equivalent Sn(5)O4 tetrahedra,  an edgeedge with one Ca(4)O6 octahedra, and edges with four equivalent Sn(6)O6 octahedra. There are nine inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form SnO6 octahedra that share  a cornercorner with one Sn(2)O4 tetrahedra, corners with two equivalent Ca(1)O4 tetrahedra, corners with two equivalent Sn(7)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra, edges with two equivalent Ca(3)O6 octahedra, and edges with two equivalent Sn(1)O6 octahedra. In the second Sn site, Sn(2) is bonded to one O(2), one O(9), and two equivalent O(4) atoms to form distorted SnO4 tetrahedra that share  a cornercorner with one Ca(3)O6 octahedra, corners with two equivalent Ca(5)O6 octahedra, corners with two equivalent Sn(1)O6 octahedra, corners with three equivalent Ca(2)O6 octahedra, and corners with four equivalent Sn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-74°. In the third Sn site, Sn(3) is bonded in a 6-coordinate geometry to one O(16), one O(3), two equivalent O(1), and two equivalent O(17) atoms. In the fourth Sn site, Sn(4) is bonded to one O(11), one O(12), one O(14), one O(4), one O(6), and one O(9) atom to form SnO6 octahedra that share  a cornercorner with one Sn(5)O4 tetrahedra,  a cornercorner with one Sn(7)O4 tetrahedra, corners with two equivalent Sn(2)O4 tetrahedra, corners with two equivalent Sn(8)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra,  an edgeedge with one Ca(4)O6 octahedra, edges with two equivalent Ca(5)O6 octahedra, and edges with two equivalent Sn(4)O6 octahedra. In the fifth Sn site, Sn(5) is bonded to one O(15), one O(6), and two equivalent O(10) atoms to form distorted SnO4 tetrahedra that share  a cornercorner with one Ca(5)O6 octahedra, corners with two equivalent Ca(6)O6 octahedra, corners with two equivalent Sn(4)O6 octahedra, corners with three equivalent Ca(4)O6 octahedra, and corners with four equivalent Sn(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-74°. In the sixth Sn site, Sn(6) is bonded to one O(10), one O(13), one O(15), one O(16), one O(17), and one O(18) atom to form SnO6 octahedra that share  a cornercorner with one Ca(1)O4 tetrahedra,  a cornercorner with one Sn(8)O4 tetrahedra, corners with two equivalent Sn(5)O4 tetrahedra,  an edgeedge with one Ca(4)O6 octahedra, edges with two equivalent Ca(6)O6 octahedra, and edges with two equivalent Sn(6)O6 octahedra. In the seventh Sn site, Sn(7) is bonded to one O(14), one O(5), and two equivalent O(7) atoms to form distorted SnO4 tetrahedra that share  a cornercorner with one Ca(5)O6 octahedra, corners with two equivalent Ca(3)O6 octahedra, corners with two equivalent Sn(4)O6 octahedra, corners with three equivalent Ca(2)O6 octahedra, and corners with four equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-73°. In the eighth Sn site, Sn(8) is bonded to one O(11), one O(18), and two equivalent O(12) atoms to form distorted SnO4 tetrahedra that share  a cornercorner with one Ca(6)O6 octahedra, corners with two equivalent Ca(5)O6 octahedra, corners with two equivalent Sn(6)O6 octahedra, corners with three equivalent Ca(4)O6 octahedra, and corners with four equivalent Sn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-74°. In the ninth Sn site, Sn(9) is bonded in a 4-coordinate geometry to one O(16), one O(8), and two equivalent O(17) atoms. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(3), one Sn(1), and one Sn(3) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(1)Ca2Sn2 tetrahedra,  a cornercorner with one O(5)CaSn3 tetrahedra, corners with three equivalent O(7)Ca2Sn2 tetrahedra,  a cornercorner with one O(16)Sn4 trigonal pyramid, and  an edgeedge with one O(1)Ca2Sn2 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(3), one Sn(2), and two equivalent Sn(1) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Sn(3), and two equivalent Sn(1) atoms. In the fourth O site, O(4) is bonded to one Ca(2), one Ca(5), one Sn(2), and one Sn(4) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(4)Ca2Sn2 tetrahedra,  a cornercorner with one O(11)CaSn3 tetrahedra,  a cornercorner with one O(5)CaSn3 tetrahedra,  a cornercorner with one O(9)CaSn3 tetrahedra, corners with two equivalent O(7)Ca2Sn2 tetrahedra, corners with three equivalent O(12)Ca2Sn2 tetrahedra,  an edgeedge with one O(4)Ca2Sn2 tetrahedra, and  an edgeedge with one O(9)CaSn3 tetrahedra. In the fifth O site, O(5) is bonded to one Ca(2), one Sn(7), and two equivalent Sn(1) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(9)CaSn3 tetrahedra, corners with two equivalent O(1)Ca2Sn2 tetrahedra, corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(7)Ca2Sn2 tetrahedra, and edges with two equivalent O(7)Ca2Sn2 tetrahedra. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(5), one Sn(5), and two equivalent Sn(4) atoms. In the seventh O site, O(7) is bonded to one Ca(2), one Ca(3), one Sn(1), and one Sn(7) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(7)Ca2Sn2 tetrahedra,  a cornercorner with one O(5)CaSn3 tetrahedra,  a cornercorner with one O(9)CaSn3 tetrahedra, corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with three equivalent O(1)Ca2Sn2 tetrahedra,  an edgeedge with one O(7)Ca2Sn2 tetrahedra, and  an edgeedge with one O(5)CaSn3 tetrahedra. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(3), one Sn(9), and two equivalent Sn(1) atoms. In the ninth O site, O(9) is bonded to one Ca(2), one Sn(2), and two equivalent Sn(4) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(5)CaSn3 tetrahedra, corners with two equivalent O(12)Ca2Sn2 tetrahedra, corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(7)Ca2Sn2 tetrahedra, corners with two equivalent O(11)CaSn3 tetrahedra, and edges with two equivalent O(4)Ca2Sn2 tetrahedra. In the tenth O site, O(10) is bonded to one Ca(4), one Ca(6), one Sn(5), and one Sn(6) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(10)Ca2Sn2 tetrahedra,  a cornercorner with one O(11)CaSn3 tetrahedra,  a cornercorner with one O(15)CaSn3 tetrahedra, corners with two equivalent O(12)Ca2Sn2 tetrahedra,  a cornercorner with one O(16)Sn4 trigonal pyramid,  an edgeedge with one O(10)Ca2Sn2 tetrahedra, and  an edgeedge with one O(15)CaSn3 tetrahedra. In the eleventh O site, O(11) is bonded to one Ca(4), one Sn(8), and two equivalent Sn(4) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(15)CaSn3 tetrahedra, corners with two equivalent O(10)Ca2Sn2 tetrahedra, corners with two equivalent O(12)Ca2Sn2 tetrahedra, corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(9)CaSn3 tetrahedra, and edges with two equivalent O(12)Ca2Sn2 tetrahedra. In the twelfth O site, O(12) is bonded to one Ca(4), one Ca(5), one Sn(4), and one Sn(8) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(12)Ca2Sn2 tetrahedra,  a cornercorner with one O(11)CaSn3 tetrahedra,  a cornercorner with one O(15)CaSn3 tetrahedra,  a cornercorner with one O(9)CaSn3 tetrahedra, corners with two equivalent O(10)Ca2Sn2 tetrahedra, corners with three equivalent O(4)Ca2Sn2 tetrahedra,  an edgeedge with one O(12)Ca2Sn2 tetrahedra, and  an edgeedge with one O(11)CaSn3 tetrahedra. In the thirteenth O site, O(13) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Ca(6), and two equivalent Sn(6) atoms. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Ca(5), one Sn(7), and two equivalent Sn(4) atoms. In the fifteenth O site, O(15) is bonded to one Ca(4), one Sn(5), and two equivalent Sn(6) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(11)CaSn3 tetrahedra, corners with two equivalent O(10)Ca2Sn2 tetrahedra, corners with two equivalent O(12)Ca2Sn2 tetrahedra, corners with two equivalent O(16)Sn4 trigonal pyramids, and edges with two equivalent O(10)Ca2Sn2 tetrahedra. In the sixteenth O site, O(16) is bonded to one Sn(3), one Sn(9), and two equivalent Sn(6) atoms to form distorted OSn4 trigonal pyramids that share corners with two equivalent O(1)Ca2Sn2 tetrahedra, corners with two equivalent O(10)Ca2Sn2 tetrahedra, and corners with two equivalent O(15)CaSn3 tetrahedra. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Ca(6), one Sn(3), one Sn(6), and one Sn(9) atom. In the eighteenth O site, O(18) is bonded in a 4-coordinate geometry to one Ca(6), one Sn(8), and two equivalent Sn(6) atoms.
Ca(SnO2)2 is Spinel-like structured and crystallizes in the monoclinic Cm space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(13), one O(3), and two equivalent O(1) atoms to form CaO4 tetrahedra that share  a cornercorner with one Ca(6)O6 octahedra, corners with two equivalent Ca(3)O6 octahedra, corners with two equivalent Sn(6)O6 octahedra, and corners with four equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-66°. The Ca(1)-O(13) bond length is 2.50 Å. The Ca(1)-O(3) bond length is 2.46 Å. Both Ca(1)-O(1) bond lengths are 2.23 Å. In the second Ca site, Ca(2) is bonded to one O(5), one O(9), two equivalent O(4), and two equivalent O(7) atoms to form distorted CaO6 octahedra that share corners with three equivalent Sn(2)O4 tetrahedra, corners with three equivalent Sn(7)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Ca(5)O6 octahedra, edges with two equivalent Sn(1)O6 octahedra, and edges with two equivalent Sn(4)O6 octahedra. The Ca(2)-O(5) bond length is 2.39 Å. The Ca(2)-O(9) bond length is 2.39 Å. Both Ca(2)-O(4) bond lengths are 2.44 Å. Both Ca(2)-O(7) bond lengths are 2.44 Å. In the third Ca site, Ca(3) is bonded to one O(2), one O(8), two equivalent O(1), and two equivalent O(7) atoms to form distorted CaO6 octahedra that share  a cornercorner with one Sn(2)O4 tetrahedra, corners with two equivalent Ca(1)O4 tetrahedra, corners with two equivalent Sn(7)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra, and edges with four equivalent Sn(1)O6 octahedra. The Ca(3)-O(2) bond length is 2.36 Å. The Ca(3)-O(8) bond length is 2.35 Å. Both Ca(3)-O(1) bond lengths are 2.39 Å. Both Ca(3)-O(7) bond lengths are 2.42 Å. In the fourth Ca site, Ca(4) is bonded to one O(11), one O(15), two equivalent O(10), and two equivalent O(12) atoms to form distorted CaO6 octahedra that share corners with three equivalent Sn(5)O4 tetrahedra, corners with three equivalent Sn(8)O4 tetrahedra,  an edgeedge with one Ca(5)O6 octahedra,  an edgeedge with one Ca(6)O6 octahedra, edges with two equivalent Sn(4)O6 octahedra, and edges with two equivalent Sn(6)O6 octahedra. The Ca(4)-O(11) bond length is 2.39 Å. The Ca(4)-O(15) bond length is 2.35 Å. Both Ca(4)-O(10) bond lengths are 2.44 Å. Both Ca(4)-O(12) bond lengths are 2.44 Å. In the fifth Ca site, Ca(5) is bonded to one O(14), one O(6), two equivalent O(12), and two equivalent O(4) atoms to form distorted CaO6 octahedra that share  a cornercorner with one Sn(5)O4 tetrahedra,  a cornercorner with one Sn(7)O4 tetrahedra, corners with two equivalent Sn(2)O4 tetrahedra, corners with two equivalent Sn(8)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra,  an edgeedge with one Ca(4)O6 octahedra, and edges with four equivalent Sn(4)O6 octahedra. The Ca(5)-O(14) bond length is 2.34 Å. The Ca(5)-O(6) bond length is 2.34 Å. Both Ca(5)-O(12) bond lengths are 2.42 Å. Both Ca(5)-O(4) bond lengths are 2.42 Å. In the sixth Ca site, Ca(6) is bonded to one O(13), one O(18), two equivalent O(10), and two equivalent O(17) atoms to form CaO6 octahedra that share  a cornercorner with one Ca(1)O4 tetrahedra,  a cornercorner with one Sn(8)O4 tetrahedra, corners with two equivalent Sn(5)O4 tetrahedra,  an edgeedge with one Ca(4)O6 octahedra, and edges with four equivalent Sn(6)O6 octahedra. The Ca(6)-O(13) bond length is 2.39 Å. The Ca(6)-O(18) bond length is 2.33 Å. Both Ca(6)-O(10) bond lengths are 2.41 Å. Both Ca(6)-O(17) bond lengths are 2.37 Å. There are nine inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form SnO6 octahedra that share  a cornercorner with one Sn(2)O4 tetrahedra, corners with two equivalent Ca(1)O4 tetrahedra, corners with two equivalent Sn(7)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra, edges with two equivalent Ca(3)O6 octahedra, and edges with two equivalent Sn(1)O6 octahedra. The Sn(1)-O(1) bond length is 2.12 Å. The Sn(1)-O(2) bond length is 2.09 Å. The Sn(1)-O(3) bond length is 2.19 Å. The Sn(1)-O(5) bond length is 2.13 Å. The Sn(1)-O(7) bond length is 2.13 Å. The Sn(1)-O(8) bond length is 2.09 Å. In the second Sn site, Sn(2) is bonded to one O(2), one O(9), and two equivalent O(4) atoms to form distorted SnO4 tetrahedra that share  a cornercorner with one Ca(3)O6 octahedra, corners with two equivalent Ca(5)O6 octahedra, corners with two equivalent Sn(1)O6 octahedra, corners with three equivalent Ca(2)O6 octahedra, and corners with four equivalent Sn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-74°. The Sn(2)-O(2) bond length is 2.71 Å. The Sn(2)-O(9) bond length is 2.59 Å. Both Sn(2)-O(4) bond lengths are 2.13 Å. In the third Sn site, Sn(3) is bonded in a 6-coordinate geometry to one O(16), one O(3), two equivalent O(1), and two equivalent O(17) atoms. The Sn(3)-O(16) bond length is 2.61 Å. The Sn(3)-O(3) bond length is 2.39 Å. Both Sn(3)-O(1) bond lengths are 2.29 Å. Both Sn(3)-O(17) bond lengths are 2.72 Å. In the fourth Sn site, Sn(4) is bonded to one O(11), one O(12), one O(14), one O(4), one O(6), and one O(9) atom to form SnO6 octahedra that share  a cornercorner with one Sn(5)O4 tetrahedra,  a cornercorner with one Sn(7)O4 tetrahedra, corners with two equivalent Sn(2)O4 tetrahedra, corners with two equivalent Sn(8)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra,  an edgeedge with one Ca(4)O6 octahedra, edges with two equivalent Ca(5)O6 octahedra, and edges with two equivalent Sn(4)O6 octahedra. The Sn(4)-O(11) bond length is 2.13 Å. The Sn(4)-O(12) bond length is 2.14 Å. The Sn(4)-O(14) bond length is 2.10 Å. The Sn(4)-O(4) bond length is 2.14 Å. The Sn(4)-O(6) bond length is 2.11 Å. The Sn(4)-O(9) bond length is 2.12 Å. In the fifth Sn site, Sn(5) is bonded to one O(15), one O(6), and two equivalent O(10) atoms to form distorted SnO4 tetrahedra that share  a cornercorner with one Ca(5)O6 octahedra, corners with two equivalent Ca(6)O6 octahedra, corners with two equivalent Sn(4)O6 octahedra, corners with three equivalent Ca(4)O6 octahedra, and corners with four equivalent Sn(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-74°. The Sn(5)-O(15) bond length is 2.65 Å. The Sn(5)-O(6) bond length is 2.72 Å. Both Sn(5)-O(10) bond lengths are 2.13 Å. In the sixth Sn site, Sn(6) is bonded to one O(10), one O(13), one O(15), one O(16), one O(17), and one O(18) atom to form SnO6 octahedra that share  a cornercorner with one Ca(1)O4 tetrahedra,  a cornercorner with one Sn(8)O4 tetrahedra, corners with two equivalent Sn(5)O4 tetrahedra,  an edgeedge with one Ca(4)O6 octahedra, edges with two equivalent Ca(6)O6 octahedra, and edges with two equivalent Sn(6)O6 octahedra. The Sn(6)-O(10) bond length is 2.14 Å. The Sn(6)-O(13) bond length is 2.18 Å. The Sn(6)-O(15) bond length is 2.10 Å. The Sn(6)-O(16) bond length is 2.12 Å. The Sn(6)-O(17) bond length is 2.11 Å. The Sn(6)-O(18) bond length is 2.11 Å. In the seventh Sn site, Sn(7) is bonded to one O(14), one O(5), and two equivalent O(7) atoms to form distorted SnO4 tetrahedra that share  a cornercorner with one Ca(5)O6 octahedra, corners with two equivalent Ca(3)O6 octahedra, corners with two equivalent Sn(4)O6 octahedra, corners with three equivalent Ca(2)O6 octahedra, and corners with four equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-73°. The Sn(7)-O(14) bond length is 2.71 Å. The Sn(7)-O(5) bond length is 2.57 Å. Both Sn(7)-O(7) bond lengths are 2.13 Å. In the eighth Sn site, Sn(8) is bonded to one O(11), one O(18), and two equivalent O(12) atoms to form distorted SnO4 tetrahedra that share  a cornercorner with one Ca(6)O6 octahedra, corners with two equivalent Ca(5)O6 octahedra, corners with two equivalent Sn(6)O6 octahedra, corners with three equivalent Ca(4)O6 octahedra, and corners with four equivalent Sn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-74°. The Sn(8)-O(11) bond length is 2.59 Å. The Sn(8)-O(18) bond length is 2.71 Å. Both Sn(8)-O(12) bond lengths are 2.14 Å. In the ninth Sn site, Sn(9) is bonded in a 4-coordinate geometry to one O(16), one O(8), and two equivalent O(17) atoms. The Sn(9)-O(16) bond length is 2.47 Å. The Sn(9)-O(8) bond length is 2.77 Å. Both Sn(9)-O(17) bond lengths are 2.10 Å. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(3), one Sn(1), and one Sn(3) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(1)Ca2Sn2 tetrahedra,  a cornercorner with one O(5)CaSn3 tetrahedra, corners with three equivalent O(7)Ca2Sn2 tetrahedra,  a cornercorner with one O(16)Sn4 trigonal pyramid, and  an edgeedge with one O(1)Ca2Sn2 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(3), one Sn(2), and two equivalent Sn(1) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Sn(3), and two equivalent Sn(1) atoms. In the fourth O site, O(4) is bonded to one Ca(2), one Ca(5), one Sn(2), and one Sn(4) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(4)Ca2Sn2 tetrahedra,  a cornercorner with one O(11)CaSn3 tetrahedra,  a cornercorner with one O(5)CaSn3 tetrahedra,  a cornercorner with one O(9)CaSn3 tetrahedra, corners with two equivalent O(7)Ca2Sn2 tetrahedra, corners with three equivalent O(12)Ca2Sn2 tetrahedra,  an edgeedge with one O(4)Ca2Sn2 tetrahedra, and  an edgeedge with one O(9)CaSn3 tetrahedra. In the fifth O site, O(5) is bonded to one Ca(2), one Sn(7), and two equivalent Sn(1) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(9)CaSn3 tetrahedra, corners with two equivalent O(1)Ca2Sn2 tetrahedra, corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(7)Ca2Sn2 tetrahedra, and edges with two equivalent O(7)Ca2Sn2 tetrahedra. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(5), one Sn(5), and two equivalent Sn(4) atoms. In the seventh O site, O(7) is bonded to one Ca(2), one Ca(3), one Sn(1), and one Sn(7) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(7)Ca2Sn2 tetrahedra,  a cornercorner with one O(5)CaSn3 tetrahedra,  a cornercorner with one O(9)CaSn3 tetrahedra, corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with three equivalent O(1)Ca2Sn2 tetrahedra,  an edgeedge with one O(7)Ca2Sn2 tetrahedra, and  an edgeedge with one O(5)CaSn3 tetrahedra. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(3), one Sn(9), and two equivalent Sn(1) atoms. In the ninth O site, O(9) is bonded to one Ca(2), one Sn(2), and two equivalent Sn(4) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(5)CaSn3 tetrahedra, corners with two equivalent O(12)Ca2Sn2 tetrahedra, corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(7)Ca2Sn2 tetrahedra, corners with two equivalent O(11)CaSn3 tetrahedra, and edges with two equivalent O(4)Ca2Sn2 tetrahedra. In the tenth O site, O(10) is bonded to one Ca(4), one Ca(6), one Sn(5), and one Sn(6) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(10)Ca2Sn2 tetrahedra,  a cornercorner with one O(11)CaSn3 tetrahedra,  a cornercorner with one O(15)CaSn3 tetrahedra, corners with two equivalent O(12)Ca2Sn2 tetrahedra,  a cornercorner with one O(16)Sn4 trigonal pyramid,  an edgeedge with one O(10)Ca2Sn2 tetrahedra, and  an edgeedge with one O(15)CaSn3 tetrahedra. In the eleventh O site, O(11) is bonded to one Ca(4), one Sn(8), and two equivalent Sn(4) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(15)CaSn3 tetrahedra, corners with two equivalent O(10)Ca2Sn2 tetrahedra, corners with two equivalent O(12)Ca2Sn2 tetrahedra, corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(9)CaSn3 tetrahedra, and edges with two equivalent O(12)Ca2Sn2 tetrahedra. In the twelfth O site, O(12) is bonded to one Ca(4), one Ca(5), one Sn(4), and one Sn(8) atom to form distorted OCa2Sn2 tetrahedra that share  a cornercorner with one O(12)Ca2Sn2 tetrahedra,  a cornercorner with one O(11)CaSn3 tetrahedra,  a cornercorner with one O(15)CaSn3 tetrahedra,  a cornercorner with one O(9)CaSn3 tetrahedra, corners with two equivalent O(10)Ca2Sn2 tetrahedra, corners with three equivalent O(4)Ca2Sn2 tetrahedra,  an edgeedge with one O(12)Ca2Sn2 tetrahedra, and  an edgeedge with one O(11)CaSn3 tetrahedra. In the thirteenth O site, O(13) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Ca(6), and two equivalent Sn(6) atoms. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Ca(5), one Sn(7), and two equivalent Sn(4) atoms. In the fifteenth O site, O(15) is bonded to one Ca(4), one Sn(5), and two equivalent Sn(6) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(11)CaSn3 tetrahedra, corners with two equivalent O(10)Ca2Sn2 tetrahedra, corners with two equivalent O(12)Ca2Sn2 tetrahedra, corners with two equivalent O(16)Sn4 trigonal pyramids, and edges with two equivalent O(10)Ca2Sn2 tetrahedra. In the sixteenth O site, O(16) is bonded to one Sn(3), one Sn(9), and two equivalent Sn(6) atoms to form distorted OSn4 trigonal pyramids that share corners with two equivalent O(1)Ca2Sn2 tetrahedra, corners with two equivalent O(10)Ca2Sn2 tetrahedra, and corners with two equivalent O(15)CaSn3 tetrahedra. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Ca(6), one Sn(3), one Sn(6), and one Sn(9) atom. In the eighteenth O site, O(18) is bonded in a 4-coordinate geometry to one Ca(6), one Sn(8), and two equivalent Sn(6) atoms.