CaSb2O4 crystallizes in the triclinic P1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(17), one O(21), one O(23), one O(3), and one O(4) atom to form distorted CaO6 pentagonal pyramids that share corners with two equivalent Ca(3)O6 octahedra, corners with two equivalent Sb(4)O5 square pyramids, and  a faceface with one Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-58°. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(12), one O(2), one O(6), one O(7), and one O(9) atom. In the third Ca site, Ca(3) is bonded to one O(1), one O(21), one O(23), one O(24), one O(3), and one O(4) atom to form CaO6 octahedra that share corners with two equivalent Ca(1)O6 pentagonal pyramids,  an edgeedge with one Sb(4)O5 square pyramid, and  a faceface with one Ca(1)O6 pentagonal pyramid. In the fourth Ca site, Ca(4) is bonded in a distorted trigonal bipyramidal geometry to one O(10), one O(14), one O(18), one O(20), and one O(22) atom. In the fifth Ca site, Ca(5) is bonded to one O(11), one O(12), one O(16), one O(5), and one O(7) atom to form distorted CaO5 trigonal bipyramids that share corners with two equivalent Sb(4)O5 square pyramids. In the sixth Ca site, Ca(6) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(15), one O(19), one O(22), and one O(6) atom. There are twelve inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(3), and one O(7) atom. In the second Sb site, Sb(2) is bonded in a 3-coordinate geometry to one O(2), one O(3), one O(4), and one O(8) atom. In the third Sb site, Sb(3) is bonded in a distorted T-shaped geometry to one O(10), one O(15), and one O(19) atom. In the fourth Sb site, Sb(4) is bonded to one O(1), one O(11), one O(2), one O(4), and one O(5) atom to form distorted SbO5 square pyramids that share corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with two equivalent Ca(5)O5 trigonal bipyramids, and  an edgeedge with one Ca(3)O6 octahedra. In the fifth Sb site, Sb(5) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(5), one O(7), and one O(9) atom. In the sixth Sb site, Sb(6) is bonded in a distorted T-shaped geometry to one O(12), one O(16), and one O(9) atom. In the seventh Sb site, Sb(7) is bonded in a 3-coordinate geometry to one O(14), one O(18), and one O(22) atom. In the eighth Sb site, Sb(8) is bonded in a rectangular see-saw-like geometry to one O(10), one O(13), one O(16), and one O(6) atom. In the ninth Sb site, Sb(9) is bonded in a 3-coordinate geometry to one O(17), one O(20), and one O(24) atom. In the tenth Sb site, Sb(10) is bonded in a rectangular see-saw-like geometry to one O(13), one O(14), one O(15), and one O(19) atom. In the eleventh Sb site, Sb(11) is bonded in a 5-coordinate geometry to one O(17), one O(18), one O(20), one O(21), and one O(23) atom. In the twelfth Sb site, Sb(12) is bonded in a 4-coordinate geometry to one O(21), one O(23), one O(24), and one O(8) atom. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(3), one Sb(1), and one Sb(4) atom to form a mixture of corner and edge-sharing OCa2Sb2 trigonal pyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(2), one Sb(1), one Sb(2), and one Sb(4) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), one Sb(1), and one Sb(2) atom. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(3), one Sb(2), and one Sb(4) atom to form a mixture of distorted corner and edge-sharing OCa2Sb2 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(5), one Sb(4), and one Sb(5) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(2), one Ca(6), and one Sb(8) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(5), one Sb(1), and one Sb(5) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Sb(12) and one Sb(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ca(2), one Sb(5), and one Sb(6) atom. In the tenth O site, O(10) is bonded in a distorted trigonal pyramidal geometry to one Ca(4), one Ca(6), one Sb(3), and one Sb(8) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to one Ca(5), one Sb(4), and one Sb(5) atom. In the twelfth O site, O(12) is bonded in a rectangular see-saw-like geometry to one Ca(2), one Ca(5), one Sb(5), and one Sb(6) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Ca(6), one Sb(10), and one Sb(8) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Ca(4), one Sb(10), and one Sb(7) atom. In the fifteenth O site, O(15) is bonded in a distorted T-shaped geometry to one Ca(6), one Sb(10), and one Sb(3) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal non-coplanar geometry to one Ca(5), one Sb(6), and one Sb(8) atom. In the seventeenth O site, O(17) is bonded in a 3-coordinate geometry to one Ca(1), one Sb(11), and one Sb(9) atom. In the eighteenth O site, O(18) is bonded in a distorted trigonal planar geometry to one Ca(4), one Sb(11), and one Sb(7) atom. In the nineteenth O site, O(19) is bonded in a 3-coordinate geometry to one Ca(6), one Sb(10), and one Sb(3) atom. In the twentieth O site, O(20) is bonded in a distorted bent 120 degrees geometry to one Ca(4), one Sb(11), and one Sb(9) atom. In the twenty-first O site, O(21) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), one Sb(11), and one Sb(12) atom. In the twenty-second O site, O(22) is bonded in a 3-coordinate geometry to one Ca(4), one Ca(6), and one Sb(7) atom. In the twenty-third O site, O(23) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Ca(3), one Sb(11), and one Sb(12) atom. In the twenty-fourth O site, O(24) is bonded in a trigonal planar geometry to one Ca(3), one Sb(12), and one Sb(9) atom.
CaSb2O4 crystallizes in the triclinic P1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(17), one O(21), one O(23), one O(3), and one O(4) atom to form distorted CaO6 pentagonal pyramids that share corners with two equivalent Ca(3)O6 octahedra, corners with two equivalent Sb(4)O5 square pyramids, and  a faceface with one Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-58°. The Ca(1)-O(1) bond length is 2.44 Å. The Ca(1)-O(17) bond length is 2.61 Å. The Ca(1)-O(21) bond length is 2.40 Å. The Ca(1)-O(23) bond length is 2.57 Å. The Ca(1)-O(3) bond length is 2.55 Å. The Ca(1)-O(4) bond length is 2.56 Å. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(12), one O(2), one O(6), one O(7), and one O(9) atom. The Ca(2)-O(12) bond length is 2.37 Å. The Ca(2)-O(2) bond length is 2.60 Å. The Ca(2)-O(6) bond length is 2.40 Å. The Ca(2)-O(7) bond length is 2.58 Å. The Ca(2)-O(9) bond length is 2.39 Å. In the third Ca site, Ca(3) is bonded to one O(1), one O(21), one O(23), one O(24), one O(3), and one O(4) atom to form CaO6 octahedra that share corners with two equivalent Ca(1)O6 pentagonal pyramids,  an edgeedge with one Sb(4)O5 square pyramid, and  a faceface with one Ca(1)O6 pentagonal pyramid. The Ca(3)-O(1) bond length is 2.56 Å. The Ca(3)-O(21) bond length is 2.41 Å. The Ca(3)-O(23) bond length is 2.42 Å. The Ca(3)-O(24) bond length is 2.39 Å. The Ca(3)-O(3) bond length is 2.39 Å. The Ca(3)-O(4) bond length is 2.41 Å. In the fourth Ca site, Ca(4) is bonded in a distorted trigonal bipyramidal geometry to one O(10), one O(14), one O(18), one O(20), and one O(22) atom. The Ca(4)-O(10) bond length is 2.31 Å. The Ca(4)-O(14) bond length is 2.52 Å. The Ca(4)-O(18) bond length is 2.37 Å. The Ca(4)-O(20) bond length is 2.26 Å. The Ca(4)-O(22) bond length is 2.48 Å. In the fifth Ca site, Ca(5) is bonded to one O(11), one O(12), one O(16), one O(5), and one O(7) atom to form distorted CaO5 trigonal bipyramids that share corners with two equivalent Sb(4)O5 square pyramids. The Ca(5)-O(11) bond length is 2.33 Å. The Ca(5)-O(12) bond length is 2.49 Å. The Ca(5)-O(16) bond length is 2.43 Å. The Ca(5)-O(5) bond length is 2.33 Å. The Ca(5)-O(7) bond length is 2.27 Å. In the sixth Ca site, Ca(6) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(15), one O(19), one O(22), and one O(6) atom. The Ca(6)-O(10) bond length is 2.63 Å. The Ca(6)-O(13) bond length is 2.41 Å. The Ca(6)-O(15) bond length is 2.46 Å. The Ca(6)-O(19) bond length is 2.27 Å. The Ca(6)-O(22) bond length is 2.26 Å. The Ca(6)-O(6) bond length is 2.49 Å. There are twelve inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(3), and one O(7) atom. The Sb(1)-O(1) bond length is 2.03 Å. The Sb(1)-O(2) bond length is 2.10 Å. The Sb(1)-O(3) bond length is 2.72 Å. The Sb(1)-O(7) bond length is 2.01 Å. In the second Sb site, Sb(2) is bonded in a 3-coordinate geometry to one O(2), one O(3), one O(4), and one O(8) atom. The Sb(2)-O(2) bond length is 2.72 Å. The Sb(2)-O(3) bond length is 1.99 Å. The Sb(2)-O(4) bond length is 2.02 Å. The Sb(2)-O(8) bond length is 2.00 Å. In the third Sb site, Sb(3) is bonded in a distorted T-shaped geometry to one O(10), one O(15), and one O(19) atom. The Sb(3)-O(10) bond length is 2.00 Å. The Sb(3)-O(15) bond length is 2.09 Å. The Sb(3)-O(19) bond length is 1.97 Å. In the fourth Sb site, Sb(4) is bonded to one O(1), one O(11), one O(2), one O(4), and one O(5) atom to form distorted SbO5 square pyramids that share corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with two equivalent Ca(5)O5 trigonal bipyramids, and  an edgeedge with one Ca(3)O6 octahedra. The Sb(4)-O(1) bond length is 2.28 Å. The Sb(4)-O(11) bond length is 2.17 Å. The Sb(4)-O(2) bond length is 2.09 Å. The Sb(4)-O(4) bond length is 2.55 Å. The Sb(4)-O(5) bond length is 2.14 Å. In the fifth Sb site, Sb(5) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(5), one O(7), and one O(9) atom. The Sb(5)-O(11) bond length is 2.02 Å. The Sb(5)-O(12) bond length is 2.49 Å. The Sb(5)-O(5) bond length is 2.08 Å. The Sb(5)-O(7) bond length is 2.74 Å. The Sb(5)-O(9) bond length is 2.08 Å. In the sixth Sb site, Sb(6) is bonded in a distorted T-shaped geometry to one O(12), one O(16), and one O(9) atom. The Sb(6)-O(12) bond length is 2.01 Å. The Sb(6)-O(16) bond length is 2.01 Å. The Sb(6)-O(9) bond length is 2.07 Å. In the seventh Sb site, Sb(7) is bonded in a 3-coordinate geometry to one O(14), one O(18), and one O(22) atom. The Sb(7)-O(14) bond length is 2.09 Å. The Sb(7)-O(18) bond length is 2.03 Å. The Sb(7)-O(22) bond length is 1.98 Å. In the eighth Sb site, Sb(8) is bonded in a rectangular see-saw-like geometry to one O(10), one O(13), one O(16), and one O(6) atom. The Sb(8)-O(10) bond length is 2.37 Å. The Sb(8)-O(13) bond length is 2.03 Å. The Sb(8)-O(16) bond length is 2.13 Å. The Sb(8)-O(6) bond length is 1.97 Å. In the ninth Sb site, Sb(9) is bonded in a 3-coordinate geometry to one O(17), one O(20), and one O(24) atom. The Sb(9)-O(17) bond length is 2.06 Å. The Sb(9)-O(20) bond length is 1.96 Å. The Sb(9)-O(24) bond length is 2.05 Å. In the tenth Sb site, Sb(10) is bonded in a rectangular see-saw-like geometry to one O(13), one O(14), one O(15), and one O(19) atom. The Sb(10)-O(13) bond length is 2.05 Å. The Sb(10)-O(14) bond length is 2.15 Å. The Sb(10)-O(15) bond length is 2.08 Å. The Sb(10)-O(19) bond length is 2.42 Å. In the eleventh Sb site, Sb(11) is bonded in a 5-coordinate geometry to one O(17), one O(18), one O(20), one O(21), and one O(23) atom. The Sb(11)-O(17) bond length is 2.07 Å. The Sb(11)-O(18) bond length is 2.19 Å. The Sb(11)-O(20) bond length is 2.64 Å. The Sb(11)-O(21) bond length is 1.99 Å. The Sb(11)-O(23) bond length is 2.28 Å. In the twelfth Sb site, Sb(12) is bonded in a 4-coordinate geometry to one O(21), one O(23), one O(24), and one O(8) atom. The Sb(12)-O(21) bond length is 2.67 Å. The Sb(12)-O(23) bond length is 2.04 Å. The Sb(12)-O(24) bond length is 2.10 Å. The Sb(12)-O(8) bond length is 1.97 Å. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(3), one Sb(1), and one Sb(4) atom to form a mixture of corner and edge-sharing OCa2Sb2 trigonal pyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(2), one Sb(1), one Sb(2), and one Sb(4) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), one Sb(1), and one Sb(2) atom. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(3), one Sb(2), and one Sb(4) atom to form a mixture of distorted corner and edge-sharing OCa2Sb2 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(5), one Sb(4), and one Sb(5) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(2), one Ca(6), and one Sb(8) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(5), one Sb(1), and one Sb(5) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Sb(12) and one Sb(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ca(2), one Sb(5), and one Sb(6) atom. In the tenth O site, O(10) is bonded in a distorted trigonal pyramidal geometry to one Ca(4), one Ca(6), one Sb(3), and one Sb(8) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to one Ca(5), one Sb(4), and one Sb(5) atom. In the twelfth O site, O(12) is bonded in a rectangular see-saw-like geometry to one Ca(2), one Ca(5), one Sb(5), and one Sb(6) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Ca(6), one Sb(10), and one Sb(8) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Ca(4), one Sb(10), and one Sb(7) atom. In the fifteenth O site, O(15) is bonded in a distorted T-shaped geometry to one Ca(6), one Sb(10), and one Sb(3) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal non-coplanar geometry to one Ca(5), one Sb(6), and one Sb(8) atom. In the seventeenth O site, O(17) is bonded in a 3-coordinate geometry to one Ca(1), one Sb(11), and one Sb(9) atom. In the eighteenth O site, O(18) is bonded in a distorted trigonal planar geometry to one Ca(4), one Sb(11), and one Sb(7) atom. In the nineteenth O site, O(19) is bonded in a 3-coordinate geometry to one Ca(6), one Sb(10), and one Sb(3) atom. In the twentieth O site, O(20) is bonded in a distorted bent 120 degrees geometry to one Ca(4), one Sb(11), and one Sb(9) atom. In the twenty-first O site, O(21) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), one Sb(11), and one Sb(12) atom. In the twenty-second O site, O(22) is bonded in a 3-coordinate geometry to one Ca(4), one Ca(6), and one Sb(7) atom. In the twenty-third O site, O(23) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Ca(3), one Sb(11), and one Sb(12) atom. In the twenty-fourth O site, O(24) is bonded in a trigonal planar geometry to one Ca(3), one Sb(12), and one Sb(9) atom.