CaCu2(SbO4)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one O(1), one O(4), one O(7), one O(8), and two equivalent O(3) atoms to form distorted CaO6 octahedra that share corners with three equivalent Sb(1)O4 tetrahedra, corners with three equivalent Sb(2)O4 tetrahedra, and  an edgeedge with one Ca(1)O6 octahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(6), and one O(7) atom. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(6), and one O(8) atom. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form SbO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-61°. In the second Sb site, Sb(2) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form SbO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-64°. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(1), and one Sb(1) atom. In the second O site, O(8) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one Sb(2) atom. In the third O site, O(1) is bonded in a trigonal planar geometry to one Ca(1), one Cu(1), and one Sb(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Cu(2) and one Sb(1) atom. In the fifth O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(1), one Cu(1), and one Sb(2) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one Sb(1) atom. In the seventh O site, O(5) is bonded in a bent 120 degrees geometry to one Cu(1) and one Sb(2) atom. In the eighth O site, O(6) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one Sb(2) atom.
CaCu2(SbO4)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to one O(1), one O(4), one O(7), one O(8), and two equivalent O(3) atoms to form distorted CaO6 octahedra that share corners with three equivalent Sb(1)O4 tetrahedra, corners with three equivalent Sb(2)O4 tetrahedra, and  an edgeedge with one Ca(1)O6 octahedra. The Ca(1)-O(1) bond length is 2.34 Å. The Ca(1)-O(4) bond length is 2.36 Å. The Ca(1)-O(7) bond length is 2.39 Å. The Ca(1)-O(8) bond length is 2.29 Å. There is one shorter (2.29 Å) and one longer (2.40 Å) Ca(1)-O(3) bond length. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(6), and one O(7) atom. The Cu(1)-O(1) bond length is 1.93 Å. The Cu(1)-O(3) bond length is 2.61 Å. The Cu(1)-O(5) bond length is 1.89 Å. The Cu(1)-O(6) bond length is 2.04 Å. The Cu(1)-O(7) bond length is 2.02 Å. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(6), and one O(8) atom. The Cu(2)-O(2) bond length is 1.92 Å. The Cu(2)-O(4) bond length is 1.98 Å. The Cu(2)-O(6) bond length is 2.00 Å. The Cu(2)-O(8) bond length is 1.96 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form SbO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-61°. The Sb(1)-O(1) bond length is 1.92 Å. The Sb(1)-O(2) bond length is 1.91 Å. The Sb(1)-O(4) bond length is 1.92 Å. The Sb(1)-O(7) bond length is 1.91 Å. In the second Sb site, Sb(2) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form SbO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-64°. The Sb(2)-O(3) bond length is 1.90 Å. The Sb(2)-O(5) bond length is 1.91 Å. The Sb(2)-O(6) bond length is 1.96 Å. The Sb(2)-O(8) bond length is 1.90 Å. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(1), and one Sb(1) atom. In the second O site, O(8) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one Sb(2) atom. In the third O site, O(1) is bonded in a trigonal planar geometry to one Ca(1), one Cu(1), and one Sb(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Cu(2) and one Sb(1) atom. In the fifth O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(1), one Cu(1), and one Sb(2) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cu(2), and one Sb(1) atom. In the seventh O site, O(5) is bonded in a bent 120 degrees geometry to one Cu(1) and one Sb(2) atom. In the eighth O site, O(6) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one Sb(2) atom.