Ca4Bi6O13 crystallizes in the monoclinic Cm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(11), one O(15), one O(2), one O(3), one O(6), one O(8), and one O(9) atom to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Ca(3)O7 pentagonal bipyramids, corners with two equivalent Ca(4)O7 pentagonal bipyramids,  a cornercorner with one Bi(1)O5 square pyramid,  an edgeedge with one Ca(1)O7 pentagonal bipyramid,  an edgeedge with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Bi(1)O5 square pyramid,  an edgeedge with one Bi(4)O5 square pyramid,  an edgeedge with one Bi(6)O5 square pyramid,  an edgeedge with one Bi(8)O5 square pyramid,  a faceface with one Ca(3)O7 pentagonal bipyramid, and  a faceface with one Ca(4)O7 pentagonal bipyramid. In the second Ca site, Ca(2) is bonded to one O(10), one O(12), one O(16), one O(2), one O(4), one O(5), and one O(8) atom to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Ca(3)O7 pentagonal bipyramids, corners with two equivalent Ca(4)O7 pentagonal bipyramids,  a cornercorner with one Bi(1)O5 square pyramid,  a cornercorner with one Bi(8)O5 square pyramid,  an edgeedge with one Ca(1)O7 pentagonal bipyramid,  an edgeedge with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Bi(1)O5 square pyramid,  an edgeedge with one Bi(6)O5 square pyramid,  a faceface with one Ca(3)O7 pentagonal bipyramid, and  a faceface with one Ca(4)O7 pentagonal bipyramid. In the third Ca site, Ca(3) is bonded to one O(11), one O(13), one O(16), one O(2), one O(4), one O(8), and one O(9) atom to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Ca(1)O7 pentagonal bipyramids, corners with two equivalent Ca(2)O7 pentagonal bipyramids,  a cornercorner with one Bi(6)O5 square pyramid,  an edgeedge with one Ca(3)O7 pentagonal bipyramid,  an edgeedge with one Ca(4)O7 pentagonal bipyramid,  an edgeedge with one Bi(1)O5 square pyramid,  an edgeedge with one Bi(4)O5 square pyramid,  an edgeedge with one Bi(6)O5 square pyramid,  a faceface with one Ca(1)O7 pentagonal bipyramid, and  a faceface with one Ca(2)O7 pentagonal bipyramid. In the fourth Ca site, Ca(4) is bonded to one O(10), one O(12), one O(14), one O(15), one O(2), one O(3), and one O(8) atom to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Ca(1)O7 pentagonal bipyramids, corners with two equivalent Ca(2)O7 pentagonal bipyramids,  a cornercorner with one Bi(4)O5 square pyramid,  a cornercorner with one Bi(6)O5 square pyramid,  an edgeedge with one Ca(3)O7 pentagonal bipyramid,  an edgeedge with one Ca(4)O7 pentagonal bipyramid,  an edgeedge with one Bi(1)O5 square pyramid,  an edgeedge with one Bi(6)O5 square pyramid,  an edgeedge with one Bi(8)O5 square pyramid,  a faceface with one Ca(1)O7 pentagonal bipyramid, and  a faceface with one Ca(2)O7 pentagonal bipyramid. There are eight inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(11), one O(12), one O(2), one O(5), and one O(6) atom to form BiO5 square pyramids that share  a cornercorner with one Ca(1)O7 pentagonal bipyramid,  a cornercorner with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Ca(1)O7 pentagonal bipyramid,  an edgeedge with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Ca(3)O7 pentagonal bipyramid,  an edgeedge with one Ca(4)O7 pentagonal bipyramid, and  an edgeedge with one Bi(8)O5 square pyramid. In the second Bi site, Bi(2) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(13), and one O(5) atom. In the third Bi site, Bi(3) is bonded in a distorted trigonal non-coplanar geometry to one O(14), one O(6), and one O(7) atom. In the fourth Bi site, Bi(4) is bonded to one O(9), two equivalent O(13), and two equivalent O(3) atoms to form distorted BiO5 square pyramids that share corners with two equivalent Ca(4)O7 pentagonal bipyramids, edges with two equivalent Ca(1)O7 pentagonal bipyramids, edges with two equivalent Ca(3)O7 pentagonal bipyramids, and edges with two equivalent Bi(6)O5 square pyramids. In the fifth Bi site, Bi(5) is bonded in a 6-coordinate geometry to one O(1), one O(10), two equivalent O(14), and two equivalent O(4) atoms. In the sixth Bi site, Bi(6) is bonded to one O(13), one O(14), one O(3), one O(4), and one O(8) atom to form BiO5 square pyramids that share  a cornercorner with one Ca(3)O7 pentagonal bipyramid,  a cornercorner with one Ca(4)O7 pentagonal bipyramid,  an edgeedge with one Ca(1)O7 pentagonal bipyramid,  an edgeedge with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Ca(3)O7 pentagonal bipyramid,  an edgeedge with one Ca(4)O7 pentagonal bipyramid, and  an edgeedge with one Bi(4)O5 square pyramid. In the seventh Bi site, Bi(7) is bonded in a 6-coordinate geometry to one O(16), one O(7), two equivalent O(11), and two equivalent O(5) atoms. In the eighth Bi site, Bi(8) is bonded to one O(15), two equivalent O(12), and two equivalent O(6) atoms to form distorted BiO5 square pyramids that share corners with two equivalent Ca(2)O7 pentagonal bipyramids, edges with two equivalent Ca(1)O7 pentagonal bipyramids, edges with two equivalent Ca(4)O7 pentagonal bipyramids, and edges with two equivalent Bi(1)O5 square pyramids. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Bi(5) and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), and one Bi(1) atom to form distorted OCa4Bi square pyramids that share corners with two equivalent O(10)Ca4Bi trigonal bipyramids, corners with two equivalent O(9)Ca4Bi trigonal bipyramids,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid, edges with two equivalent O(8)Ca4Bi square pyramids,  an edgeedge with one O(15)Ca4Bi trigonal bipyramid,  an edgeedge with one O(16)Ca4Bi trigonal bipyramid,  an edgeedge with one O(11)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(12)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(3)Ca2Bi2 trigonal pyramid, and  an edgeedge with one O(4)Ca2Bi2 trigonal pyramid. In the third O site, O(3) is bonded to one Ca(1), one Ca(4), one Bi(4), and one Bi(6) atom to form OCa2Bi2 trigonal pyramids that share  a cornercorner with one O(8)Ca4Bi square pyramid,  a cornercorner with one O(10)Ca4Bi trigonal bipyramid,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(2)Ca4Bi square pyramid,  an edgeedge with one O(8)Ca4Bi square pyramid,  an edgeedge with one O(15)Ca4Bi trigonal bipyramid, and  an edgeedge with one O(9)Ca4Bi trigonal bipyramid. In the fourth O site, O(4) is bonded to one Ca(2), one Ca(3), one Bi(5), and one Bi(6) atom to form OCa2Bi2 trigonal pyramids that share  a cornercorner with one O(8)Ca4Bi square pyramid,  a cornercorner with one O(9)Ca4Bi trigonal bipyramid,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(2)Ca4Bi square pyramid,  an edgeedge with one O(8)Ca4Bi square pyramid,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid, and  an edgeedge with one O(16)Ca4Bi trigonal bipyramid. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(2), one Bi(1), one Bi(2), and one Bi(7) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Bi(1), one Bi(3), and one Bi(8) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Bi(7) and two equivalent Bi(3) atoms. In the eighth O site, O(8) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), and one Bi(6) atom to form distorted OCa4Bi square pyramids that share corners with two equivalent O(15)Ca4Bi trigonal bipyramids, corners with two equivalent O(16)Ca4Bi trigonal bipyramids,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid, edges with two equivalent O(2)Ca4Bi square pyramids,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid,  an edgeedge with one O(9)Ca4Bi trigonal bipyramid,  an edgeedge with one O(11)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(12)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(3)Ca2Bi2 trigonal pyramid, and  an edgeedge with one O(4)Ca2Bi2 trigonal pyramid. In the ninth O site, O(9) is bonded to two equivalent Ca(1), two equivalent Ca(3), and one Bi(4) atom to form distorted OCa4Bi trigonal bipyramids that share corners with four equivalent O(2)Ca4Bi square pyramids, corners with two equivalent O(4)Ca2Bi2 trigonal pyramids, edges with two equivalent O(8)Ca4Bi square pyramids,  an edgeedge with one O(15)Ca4Bi trigonal bipyramid,  an edgeedge with one O(16)Ca4Bi trigonal bipyramid, edges with two equivalent O(11)Ca2Bi2 trigonal pyramids, and edges with two equivalent O(3)Ca2Bi2 trigonal pyramids. In the tenth O site, O(10) is bonded to two equivalent Ca(2), two equivalent Ca(4), and one Bi(5) atom to form distorted OCa4Bi trigonal bipyramids that share corners with four equivalent O(2)Ca4Bi square pyramids, corners with two equivalent O(3)Ca2Bi2 trigonal pyramids, edges with two equivalent O(8)Ca4Bi square pyramids,  an edgeedge with one O(15)Ca4Bi trigonal bipyramid,  an edgeedge with one O(16)Ca4Bi trigonal bipyramid, edges with two equivalent O(12)Ca2Bi2 trigonal pyramids, and edges with two equivalent O(4)Ca2Bi2 trigonal pyramids. In the eleventh O site, O(11) is bonded to one Ca(1), one Ca(3), one Bi(1), and one Bi(7) atom to form OCa2Bi2 trigonal pyramids that share  a cornercorner with one O(2)Ca4Bi square pyramid,  a cornercorner with one O(15)Ca4Bi trigonal bipyramid,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(2)Ca4Bi square pyramid,  an edgeedge with one O(8)Ca4Bi square pyramid,  an edgeedge with one O(16)Ca4Bi trigonal bipyramid, and  an edgeedge with one O(9)Ca4Bi trigonal bipyramid. In the twelfth O site, O(12) is bonded to one Ca(2), one Ca(4), one Bi(1), and one Bi(8) atom to form OCa2Bi2 trigonal pyramids that share  a cornercorner with one O(2)Ca4Bi square pyramid,  a cornercorner with one O(16)Ca4Bi trigonal bipyramid,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(2)Ca4Bi square pyramid,  an edgeedge with one O(8)Ca4Bi square pyramid,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid, and  an edgeedge with one O(15)Ca4Bi trigonal bipyramid. In the thirteenth O site, O(13) is bonded in a distorted rectangular see-saw-like geometry to one Ca(3), one Bi(2), one Bi(4), and one Bi(6) atom. In the fourteenth O site, O(14) is bonded in a distorted rectangular see-saw-like geometry to one Ca(4), one Bi(3), one Bi(5), and one Bi(6) atom. In the fifteenth O site, O(15) is bonded to two equivalent Ca(1), two equivalent Ca(4), and one Bi(8) atom to form distorted OCa4Bi trigonal bipyramids that share corners with four equivalent O(8)Ca4Bi square pyramids, corners with two equivalent O(11)Ca2Bi2 trigonal pyramids, edges with two equivalent O(2)Ca4Bi square pyramids,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid,  an edgeedge with one O(9)Ca4Bi trigonal bipyramid, edges with two equivalent O(12)Ca2Bi2 trigonal pyramids, and edges with two equivalent O(3)Ca2Bi2 trigonal pyramids. In the sixteenth O site, O(16) is bonded to two equivalent Ca(2), two equivalent Ca(3), and one Bi(7) atom to form distorted OCa4Bi trigonal bipyramids that share corners with four equivalent O(8)Ca4Bi square pyramids, corners with two equivalent O(12)Ca2Bi2 trigonal pyramids, edges with two equivalent O(2)Ca4Bi square pyramids,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid,  an edgeedge with one O(9)Ca4Bi trigonal bipyramid, edges with two equivalent O(11)Ca2Bi2 trigonal pyramids, and edges with two equivalent O(4)Ca2Bi2 trigonal pyramids.
Ca4Bi6O13 crystallizes in the monoclinic Cm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(11), one O(15), one O(2), one O(3), one O(6), one O(8), and one O(9) atom to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Ca(3)O7 pentagonal bipyramids, corners with two equivalent Ca(4)O7 pentagonal bipyramids,  a cornercorner with one Bi(1)O5 square pyramid,  an edgeedge with one Ca(1)O7 pentagonal bipyramid,  an edgeedge with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Bi(1)O5 square pyramid,  an edgeedge with one Bi(4)O5 square pyramid,  an edgeedge with one Bi(6)O5 square pyramid,  an edgeedge with one Bi(8)O5 square pyramid,  a faceface with one Ca(3)O7 pentagonal bipyramid, and  a faceface with one Ca(4)O7 pentagonal bipyramid. The Ca(1)-O(11) bond length is 2.39 Å. The Ca(1)-O(15) bond length is 2.49 Å. The Ca(1)-O(2) bond length is 2.54 Å. The Ca(1)-O(3) bond length is 2.53 Å. The Ca(1)-O(6) bond length is 2.41 Å. The Ca(1)-O(8) bond length is 2.49 Å. The Ca(1)-O(9) bond length is 2.52 Å. In the second Ca site, Ca(2) is bonded to one O(10), one O(12), one O(16), one O(2), one O(4), one O(5), and one O(8) atom to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Ca(3)O7 pentagonal bipyramids, corners with two equivalent Ca(4)O7 pentagonal bipyramids,  a cornercorner with one Bi(1)O5 square pyramid,  a cornercorner with one Bi(8)O5 square pyramid,  an edgeedge with one Ca(1)O7 pentagonal bipyramid,  an edgeedge with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Bi(1)O5 square pyramid,  an edgeedge with one Bi(6)O5 square pyramid,  a faceface with one Ca(3)O7 pentagonal bipyramid, and  a faceface with one Ca(4)O7 pentagonal bipyramid. The Ca(2)-O(10) bond length is 2.50 Å. The Ca(2)-O(12) bond length is 2.41 Å. The Ca(2)-O(16) bond length is 2.49 Å. The Ca(2)-O(2) bond length is 2.55 Å. The Ca(2)-O(4) bond length is 2.50 Å. The Ca(2)-O(5) bond length is 2.41 Å. The Ca(2)-O(8) bond length is 2.50 Å. In the third Ca site, Ca(3) is bonded to one O(11), one O(13), one O(16), one O(2), one O(4), one O(8), and one O(9) atom to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Ca(1)O7 pentagonal bipyramids, corners with two equivalent Ca(2)O7 pentagonal bipyramids,  a cornercorner with one Bi(6)O5 square pyramid,  an edgeedge with one Ca(3)O7 pentagonal bipyramid,  an edgeedge with one Ca(4)O7 pentagonal bipyramid,  an edgeedge with one Bi(1)O5 square pyramid,  an edgeedge with one Bi(4)O5 square pyramid,  an edgeedge with one Bi(6)O5 square pyramid,  a faceface with one Ca(1)O7 pentagonal bipyramid, and  a faceface with one Ca(2)O7 pentagonal bipyramid. The Ca(3)-O(11) bond length is 2.50 Å. The Ca(3)-O(13) bond length is 2.41 Å. The Ca(3)-O(16) bond length is 2.50 Å. The Ca(3)-O(2) bond length is 2.50 Å. The Ca(3)-O(4) bond length is 2.39 Å. The Ca(3)-O(8) bond length is 2.55 Å. The Ca(3)-O(9) bond length is 2.49 Å. In the fourth Ca site, Ca(4) is bonded to one O(10), one O(12), one O(14), one O(15), one O(2), one O(3), and one O(8) atom to form distorted CaO7 pentagonal bipyramids that share corners with two equivalent Ca(1)O7 pentagonal bipyramids, corners with two equivalent Ca(2)O7 pentagonal bipyramids,  a cornercorner with one Bi(4)O5 square pyramid,  a cornercorner with one Bi(6)O5 square pyramid,  an edgeedge with one Ca(3)O7 pentagonal bipyramid,  an edgeedge with one Ca(4)O7 pentagonal bipyramid,  an edgeedge with one Bi(1)O5 square pyramid,  an edgeedge with one Bi(6)O5 square pyramid,  an edgeedge with one Bi(8)O5 square pyramid,  a faceface with one Ca(1)O7 pentagonal bipyramid, and  a faceface with one Ca(2)O7 pentagonal bipyramid. The Ca(4)-O(10) bond length is 2.49 Å. The Ca(4)-O(12) bond length is 2.52 Å. The Ca(4)-O(14) bond length is 2.41 Å. The Ca(4)-O(15) bond length is 2.52 Å. The Ca(4)-O(2) bond length is 2.49 Å. The Ca(4)-O(3) bond length is 2.40 Å. The Ca(4)-O(8) bond length is 2.55 Å. There are eight inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(11), one O(12), one O(2), one O(5), and one O(6) atom to form BiO5 square pyramids that share  a cornercorner with one Ca(1)O7 pentagonal bipyramid,  a cornercorner with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Ca(1)O7 pentagonal bipyramid,  an edgeedge with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Ca(3)O7 pentagonal bipyramid,  an edgeedge with one Ca(4)O7 pentagonal bipyramid, and  an edgeedge with one Bi(8)O5 square pyramid. The Bi(1)-O(11) bond length is 2.33 Å. The Bi(1)-O(12) bond length is 2.33 Å. The Bi(1)-O(2) bond length is 2.10 Å. The Bi(1)-O(5) bond length is 2.45 Å. The Bi(1)-O(6) bond length is 2.42 Å. In the second Bi site, Bi(2) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(13), and one O(5) atom. The Bi(2)-O(1) bond length is 2.10 Å. The Bi(2)-O(13) bond length is 2.11 Å. The Bi(2)-O(5) bond length is 2.11 Å. In the third Bi site, Bi(3) is bonded in a distorted trigonal non-coplanar geometry to one O(14), one O(6), and one O(7) atom. The Bi(3)-O(14) bond length is 2.11 Å. The Bi(3)-O(6) bond length is 2.11 Å. The Bi(3)-O(7) bond length is 2.10 Å. In the fourth Bi site, Bi(4) is bonded to one O(9), two equivalent O(13), and two equivalent O(3) atoms to form distorted BiO5 square pyramids that share corners with two equivalent Ca(4)O7 pentagonal bipyramids, edges with two equivalent Ca(1)O7 pentagonal bipyramids, edges with two equivalent Ca(3)O7 pentagonal bipyramids, and edges with two equivalent Bi(6)O5 square pyramids. The Bi(4)-O(9) bond length is 2.12 Å. Both Bi(4)-O(13) bond lengths are 2.61 Å. Both Bi(4)-O(3) bond lengths are 2.26 Å. In the fifth Bi site, Bi(5) is bonded in a 6-coordinate geometry to one O(1), one O(10), two equivalent O(14), and two equivalent O(4) atoms. The Bi(5)-O(1) bond length is 2.85 Å. The Bi(5)-O(10) bond length is 2.13 Å. Both Bi(5)-O(14) bond lengths are 2.61 Å. Both Bi(5)-O(4) bond lengths are 2.27 Å. In the sixth Bi site, Bi(6) is bonded to one O(13), one O(14), one O(3), one O(4), and one O(8) atom to form BiO5 square pyramids that share  a cornercorner with one Ca(3)O7 pentagonal bipyramid,  a cornercorner with one Ca(4)O7 pentagonal bipyramid,  an edgeedge with one Ca(1)O7 pentagonal bipyramid,  an edgeedge with one Ca(2)O7 pentagonal bipyramid,  an edgeedge with one Ca(3)O7 pentagonal bipyramid,  an edgeedge with one Ca(4)O7 pentagonal bipyramid, and  an edgeedge with one Bi(4)O5 square pyramid. The Bi(6)-O(13) bond length is 2.42 Å. The Bi(6)-O(14) bond length is 2.45 Å. The Bi(6)-O(3) bond length is 2.33 Å. The Bi(6)-O(4) bond length is 2.32 Å. The Bi(6)-O(8) bond length is 2.10 Å. In the seventh Bi site, Bi(7) is bonded in a 6-coordinate geometry to one O(16), one O(7), two equivalent O(11), and two equivalent O(5) atoms. The Bi(7)-O(16) bond length is 2.13 Å. The Bi(7)-O(7) bond length is 2.85 Å. Both Bi(7)-O(11) bond lengths are 2.27 Å. Both Bi(7)-O(5) bond lengths are 2.61 Å. In the eighth Bi site, Bi(8) is bonded to one O(15), two equivalent O(12), and two equivalent O(6) atoms to form distorted BiO5 square pyramids that share corners with two equivalent Ca(2)O7 pentagonal bipyramids, edges with two equivalent Ca(1)O7 pentagonal bipyramids, edges with two equivalent Ca(4)O7 pentagonal bipyramids, and edges with two equivalent Bi(1)O5 square pyramids. The Bi(8)-O(15) bond length is 2.12 Å. Both Bi(8)-O(12) bond lengths are 2.26 Å. Both Bi(8)-O(6) bond lengths are 2.62 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Bi(5) and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), and one Bi(1) atom to form distorted OCa4Bi square pyramids that share corners with two equivalent O(10)Ca4Bi trigonal bipyramids, corners with two equivalent O(9)Ca4Bi trigonal bipyramids,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid, edges with two equivalent O(8)Ca4Bi square pyramids,  an edgeedge with one O(15)Ca4Bi trigonal bipyramid,  an edgeedge with one O(16)Ca4Bi trigonal bipyramid,  an edgeedge with one O(11)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(12)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(3)Ca2Bi2 trigonal pyramid, and  an edgeedge with one O(4)Ca2Bi2 trigonal pyramid. In the third O site, O(3) is bonded to one Ca(1), one Ca(4), one Bi(4), and one Bi(6) atom to form OCa2Bi2 trigonal pyramids that share  a cornercorner with one O(8)Ca4Bi square pyramid,  a cornercorner with one O(10)Ca4Bi trigonal bipyramid,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(2)Ca4Bi square pyramid,  an edgeedge with one O(8)Ca4Bi square pyramid,  an edgeedge with one O(15)Ca4Bi trigonal bipyramid, and  an edgeedge with one O(9)Ca4Bi trigonal bipyramid. In the fourth O site, O(4) is bonded to one Ca(2), one Ca(3), one Bi(5), and one Bi(6) atom to form OCa2Bi2 trigonal pyramids that share  a cornercorner with one O(8)Ca4Bi square pyramid,  a cornercorner with one O(9)Ca4Bi trigonal bipyramid,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(2)Ca4Bi square pyramid,  an edgeedge with one O(8)Ca4Bi square pyramid,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid, and  an edgeedge with one O(16)Ca4Bi trigonal bipyramid. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(2), one Bi(1), one Bi(2), and one Bi(7) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Bi(1), one Bi(3), and one Bi(8) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Bi(7) and two equivalent Bi(3) atoms. In the eighth O site, O(8) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), and one Bi(6) atom to form distorted OCa4Bi square pyramids that share corners with two equivalent O(15)Ca4Bi trigonal bipyramids, corners with two equivalent O(16)Ca4Bi trigonal bipyramids,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid, edges with two equivalent O(2)Ca4Bi square pyramids,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid,  an edgeedge with one O(9)Ca4Bi trigonal bipyramid,  an edgeedge with one O(11)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(12)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(3)Ca2Bi2 trigonal pyramid, and  an edgeedge with one O(4)Ca2Bi2 trigonal pyramid. In the ninth O site, O(9) is bonded to two equivalent Ca(1), two equivalent Ca(3), and one Bi(4) atom to form distorted OCa4Bi trigonal bipyramids that share corners with four equivalent O(2)Ca4Bi square pyramids, corners with two equivalent O(4)Ca2Bi2 trigonal pyramids, edges with two equivalent O(8)Ca4Bi square pyramids,  an edgeedge with one O(15)Ca4Bi trigonal bipyramid,  an edgeedge with one O(16)Ca4Bi trigonal bipyramid, edges with two equivalent O(11)Ca2Bi2 trigonal pyramids, and edges with two equivalent O(3)Ca2Bi2 trigonal pyramids. In the tenth O site, O(10) is bonded to two equivalent Ca(2), two equivalent Ca(4), and one Bi(5) atom to form distorted OCa4Bi trigonal bipyramids that share corners with four equivalent O(2)Ca4Bi square pyramids, corners with two equivalent O(3)Ca2Bi2 trigonal pyramids, edges with two equivalent O(8)Ca4Bi square pyramids,  an edgeedge with one O(15)Ca4Bi trigonal bipyramid,  an edgeedge with one O(16)Ca4Bi trigonal bipyramid, edges with two equivalent O(12)Ca2Bi2 trigonal pyramids, and edges with two equivalent O(4)Ca2Bi2 trigonal pyramids. In the eleventh O site, O(11) is bonded to one Ca(1), one Ca(3), one Bi(1), and one Bi(7) atom to form OCa2Bi2 trigonal pyramids that share  a cornercorner with one O(2)Ca4Bi square pyramid,  a cornercorner with one O(15)Ca4Bi trigonal bipyramid,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(2)Ca4Bi square pyramid,  an edgeedge with one O(8)Ca4Bi square pyramid,  an edgeedge with one O(16)Ca4Bi trigonal bipyramid, and  an edgeedge with one O(9)Ca4Bi trigonal bipyramid. In the twelfth O site, O(12) is bonded to one Ca(2), one Ca(4), one Bi(1), and one Bi(8) atom to form OCa2Bi2 trigonal pyramids that share  a cornercorner with one O(2)Ca4Bi square pyramid,  a cornercorner with one O(16)Ca4Bi trigonal bipyramid,  a cornercorner with one O(11)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(12)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(3)Ca2Bi2 trigonal pyramid,  a cornercorner with one O(4)Ca2Bi2 trigonal pyramid,  an edgeedge with one O(2)Ca4Bi square pyramid,  an edgeedge with one O(8)Ca4Bi square pyramid,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid, and  an edgeedge with one O(15)Ca4Bi trigonal bipyramid. In the thirteenth O site, O(13) is bonded in a distorted rectangular see-saw-like geometry to one Ca(3), one Bi(2), one Bi(4), and one Bi(6) atom. In the fourteenth O site, O(14) is bonded in a distorted rectangular see-saw-like geometry to one Ca(4), one Bi(3), one Bi(5), and one Bi(6) atom. In the fifteenth O site, O(15) is bonded to two equivalent Ca(1), two equivalent Ca(4), and one Bi(8) atom to form distorted OCa4Bi trigonal bipyramids that share corners with four equivalent O(8)Ca4Bi square pyramids, corners with two equivalent O(11)Ca2Bi2 trigonal pyramids, edges with two equivalent O(2)Ca4Bi square pyramids,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid,  an edgeedge with one O(9)Ca4Bi trigonal bipyramid, edges with two equivalent O(12)Ca2Bi2 trigonal pyramids, and edges with two equivalent O(3)Ca2Bi2 trigonal pyramids. In the sixteenth O site, O(16) is bonded to two equivalent Ca(2), two equivalent Ca(3), and one Bi(7) atom to form distorted OCa4Bi trigonal bipyramids that share corners with four equivalent O(8)Ca4Bi square pyramids, corners with two equivalent O(12)Ca2Bi2 trigonal pyramids, edges with two equivalent O(2)Ca4Bi square pyramids,  an edgeedge with one O(10)Ca4Bi trigonal bipyramid,  an edgeedge with one O(9)Ca4Bi trigonal bipyramid, edges with two equivalent O(11)Ca2Bi2 trigonal pyramids, and edges with two equivalent O(4)Ca2Bi2 trigonal pyramids.