Ca2AgSbO6 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(2), and four equivalent O(1) atoms. In the second Ca site, Ca(2) is bonded to one O(3), one O(4), and four equivalent O(2) atoms to form distorted CaO6 pentagonal pyramids that share corners with two equivalent Sb(1)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and edges with two equivalent Ca(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 56°. Ag(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Ca(2)O6 pentagonal pyramids, and edges with two equivalent Ca(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 41°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1), one Ag(1), and one Sb(1) atom to form distorted OCa2AgSb trigonal pyramids that share corners with two equivalent O(3)Ca2Sb2 tetrahedra, corners with two equivalent O(4)Ca2Ag2 trigonal pyramids, corners with six equivalent O(1)Ca2AgSb trigonal pyramids,  an edgeedge with one O(3)Ca2Sb2 tetrahedra,  an edgeedge with one O(4)Ca2Ag2 trigonal pyramid, and  an edgeedge with one O(1)Ca2AgSb trigonal pyramid. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Ca(2), and one Sb(1) atom. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), and two equivalent Sb(1) atoms to form OCa2Sb2 tetrahedra that share corners with two equivalent O(3)Ca2Sb2 tetrahedra, corners with two equivalent O(4)Ca2Ag2 trigonal pyramids, corners with four equivalent O(1)Ca2AgSb trigonal pyramids, and edges with two equivalent O(1)Ca2AgSb trigonal pyramids. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), and two equivalent Ag(1) atoms to form distorted OCa2Ag2 trigonal pyramids that share corners with two equivalent O(3)Ca2Sb2 tetrahedra, corners with two equivalent O(4)Ca2Ag2 trigonal pyramids, corners with four equivalent O(1)Ca2AgSb trigonal pyramids, and edges with two equivalent O(1)Ca2AgSb trigonal pyramids.
Ca2AgSbO6 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(2), and four equivalent O(1) atoms. The Ca(1)-O(3) bond length is 2.46 Å. The Ca(1)-O(4) bond length is 2.43 Å. Both Ca(1)-O(2) bond lengths are 2.60 Å. There are two shorter (2.42 Å) and two longer (2.63 Å) Ca(1)-O(1) bond lengths. In the second Ca site, Ca(2) is bonded to one O(3), one O(4), and four equivalent O(2) atoms to form distorted CaO6 pentagonal pyramids that share corners with two equivalent Sb(1)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and edges with two equivalent Ca(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 56°. The Ca(2)-O(3) bond length is 2.39 Å. The Ca(2)-O(4) bond length is 2.33 Å. There are two shorter (2.31 Å) and two longer (2.62 Å) Ca(2)-O(2) bond lengths. Ag(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. Both Ag(1)-O(1) bond lengths are 2.07 Å. Both Ag(1)-O(4) bond lengths are 2.04 Å. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Ca(2)O6 pentagonal pyramids, and edges with two equivalent Ca(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 41°. Both Sb(1)-O(1) bond lengths are 2.05 Å. Both Sb(1)-O(2) bond lengths are 1.98 Å. Both Sb(1)-O(3) bond lengths are 2.06 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1), one Ag(1), and one Sb(1) atom to form distorted OCa2AgSb trigonal pyramids that share corners with two equivalent O(3)Ca2Sb2 tetrahedra, corners with two equivalent O(4)Ca2Ag2 trigonal pyramids, corners with six equivalent O(1)Ca2AgSb trigonal pyramids,  an edgeedge with one O(3)Ca2Sb2 tetrahedra,  an edgeedge with one O(4)Ca2Ag2 trigonal pyramid, and  an edgeedge with one O(1)Ca2AgSb trigonal pyramid. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Ca(2), and one Sb(1) atom. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), and two equivalent Sb(1) atoms to form OCa2Sb2 tetrahedra that share corners with two equivalent O(3)Ca2Sb2 tetrahedra, corners with two equivalent O(4)Ca2Ag2 trigonal pyramids, corners with four equivalent O(1)Ca2AgSb trigonal pyramids, and edges with two equivalent O(1)Ca2AgSb trigonal pyramids. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), and two equivalent Ag(1) atoms to form distorted OCa2Ag2 trigonal pyramids that share corners with two equivalent O(3)Ca2Sb2 tetrahedra, corners with two equivalent O(4)Ca2Ag2 trigonal pyramids, corners with four equivalent O(1)Ca2AgSb trigonal pyramids, and edges with two equivalent O(1)Ca2AgSb trigonal pyramids.