Ca(SnO2)2 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(3) and three equivalent O(4) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra and corners with nine equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-65°. In the second Ca site, Ca(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form distorted CaO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Sn(1)O4 tetrahedra, and edges with six equivalent Sn(2)O6 octahedra. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(2) and three equivalent O(1) atoms to form SnO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra and corners with nine equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-67°. In the second Sn site, Sn(2) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form SnO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Sn(1)O4 tetrahedra, edges with two equivalent Ca(2)O6 octahedra, and edges with four equivalent Sn(2)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ca(2), one Sn(1), and two equivalent Sn(2) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(2)Sn4 tetrahedra, corners with two equivalent O(1)CaSn3 tetrahedra, corners with seven equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(3)CaSn3 trigonal pyramids,  an edgeedge with one O(2)Sn4 tetrahedra, and edges with two equivalent O(1)CaSn3 tetrahedra. In the second O site, O(2) is bonded to one Sn(1) and three equivalent Sn(2) atoms to form distorted OSn4 tetrahedra that share corners with three equivalent O(1)CaSn3 tetrahedra, corners with six equivalent O(4)Ca2Sn2 tetrahedra, corners with three equivalent O(3)CaSn3 trigonal pyramids, and edges with three equivalent O(1)CaSn3 tetrahedra. In the third O site, O(3) is bonded to one Ca(1) and three equivalent Sn(2) atoms to form distorted OCaSn3 trigonal pyramids that share corners with three equivalent O(4)Ca2Sn2 tetrahedra, corners with three equivalent O(2)Sn4 tetrahedra, corners with six equivalent O(1)CaSn3 tetrahedra, and edges with three equivalent O(4)Ca2Sn2 tetrahedra. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), and two equivalent Sn(2) atoms to form distorted OCa2Sn2 tetrahedra that share corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(2)Sn4 tetrahedra, corners with seven equivalent O(1)CaSn3 tetrahedra,  a cornercorner with one O(3)CaSn3 trigonal pyramid, edges with two equivalent O(4)Ca2Sn2 tetrahedra, and  an edgeedge with one O(3)CaSn3 trigonal pyramid.
Ca(SnO2)2 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(3) and three equivalent O(4) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra and corners with nine equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-65°. The Ca(1)-O(3) bond length is 2.48 Å. All Ca(1)-O(4) bond lengths are 2.29 Å. In the second Ca site, Ca(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form distorted CaO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Sn(1)O4 tetrahedra, and edges with six equivalent Sn(2)O6 octahedra. All Ca(2)-O(1) bond lengths are 2.43 Å. All Ca(2)-O(4) bond lengths are 2.39 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(2) and three equivalent O(1) atoms to form SnO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra and corners with nine equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-67°. The Sn(1)-O(2) bond length is 2.67 Å. All Sn(1)-O(1) bond lengths are 2.31 Å. In the second Sn site, Sn(2) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form SnO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Sn(1)O4 tetrahedra, edges with two equivalent Ca(2)O6 octahedra, and edges with four equivalent Sn(2)O6 octahedra. The Sn(2)-O(2) bond length is 2.19 Å. The Sn(2)-O(3) bond length is 2.26 Å. Both Sn(2)-O(1) bond lengths are 2.21 Å. Both Sn(2)-O(4) bond lengths are 2.21 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ca(2), one Sn(1), and two equivalent Sn(2) atoms to form distorted OCaSn3 tetrahedra that share  a cornercorner with one O(2)Sn4 tetrahedra, corners with two equivalent O(1)CaSn3 tetrahedra, corners with seven equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(3)CaSn3 trigonal pyramids,  an edgeedge with one O(2)Sn4 tetrahedra, and edges with two equivalent O(1)CaSn3 tetrahedra. In the second O site, O(2) is bonded to one Sn(1) and three equivalent Sn(2) atoms to form distorted OSn4 tetrahedra that share corners with three equivalent O(1)CaSn3 tetrahedra, corners with six equivalent O(4)Ca2Sn2 tetrahedra, corners with three equivalent O(3)CaSn3 trigonal pyramids, and edges with three equivalent O(1)CaSn3 tetrahedra. In the third O site, O(3) is bonded to one Ca(1) and three equivalent Sn(2) atoms to form distorted OCaSn3 trigonal pyramids that share corners with three equivalent O(4)Ca2Sn2 tetrahedra, corners with three equivalent O(2)Sn4 tetrahedra, corners with six equivalent O(1)CaSn3 tetrahedra, and edges with three equivalent O(4)Ca2Sn2 tetrahedra. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), and two equivalent Sn(2) atoms to form distorted OCa2Sn2 tetrahedra that share corners with two equivalent O(4)Ca2Sn2 tetrahedra, corners with two equivalent O(2)Sn4 tetrahedra, corners with seven equivalent O(1)CaSn3 tetrahedra,  a cornercorner with one O(3)CaSn3 trigonal pyramid, edges with two equivalent O(4)Ca2Sn2 tetrahedra, and  an edgeedge with one O(3)CaSn3 trigonal pyramid.