CaBi2O4 is Spinel-like structured and crystallizes in the trigonal P3m1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(9) and three equivalent O(1) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(5)O6 octahedra, corners with three equivalent Bi(5)O6 octahedra, and corners with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the second Ca site, Ca(2) is bonded to one O(2) and three equivalent O(3) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra, corners with three equivalent Bi(1)O6 octahedra, and corners with six equivalent Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the third Ca site, Ca(3) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form CaO6 octahedra that share corners with three equivalent Ca(2)O4 tetrahedra, corners with three equivalent Bi(4)O4 tetrahedra, edges with three equivalent Bi(1)O6 octahedra, and edges with three equivalent Bi(2)O6 octahedra. In the fourth Ca site, Ca(4) is bonded to one O(5) and three equivalent O(7) atoms to form CaO4 tetrahedra that share corners with three equivalent Bi(2)O6 octahedra, corners with three equivalent Bi(3)O6 octahedra, and corners with six equivalent Bi(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-60°. In the fifth Ca site, Ca(5) is bonded to three equivalent O(1) and three equivalent O(11) atoms to form CaO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Bi(6)O4 tetrahedra, edges with three equivalent Bi(1)O6 octahedra, and edges with three equivalent Bi(5)O6 octahedra. In the sixth Ca site, Ca(6) is bonded to one O(12) and three equivalent O(8) atoms to form CaO4 tetrahedra that share corners with three equivalent Bi(3)O6 octahedra, corners with three equivalent Bi(5)O6 octahedra, and corners with six equivalent Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-59°. There are six inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(2), one O(6), two equivalent O(1), and two equivalent O(4) atoms to form BiO6 octahedra that share  a cornercorner with one Ca(2)O4 tetrahedra,  a cornercorner with one Bi(6)O4 tetrahedra, corners with two equivalent Ca(1)O4 tetrahedra, corners with two equivalent Bi(4)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Ca(5)O6 octahedra, and edges with four equivalent Bi(1)O6 octahedra. In the second Bi site, Bi(2) is bonded to one O(10), one O(5), two equivalent O(3), and two equivalent O(8) atoms to form BiO6 octahedra that share  a cornercorner with one Ca(4)O4 tetrahedra,  a cornercorner with one Bi(4)O4 tetrahedra, corners with two equivalent Ca(2)O4 tetrahedra, corners with two equivalent Ca(6)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Bi(3)O6 octahedra, and edges with four equivalent Bi(2)O6 octahedra. In the third Bi site, Bi(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form BiO6 octahedra that share corners with three equivalent Ca(4)O4 tetrahedra, corners with three equivalent Ca(6)O4 tetrahedra, edges with three equivalent Bi(2)O6 octahedra, and edges with three equivalent Bi(5)O6 octahedra. In the fourth Bi site, Bi(4) is bonded to one O(10) and three equivalent O(4) atoms to form BiO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra, corners with three equivalent Bi(2)O6 octahedra, and corners with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-59°. In the fifth Bi site, Bi(5) is bonded to one O(12), one O(9), two equivalent O(11), and two equivalent O(7) atoms to form BiO6 octahedra that share  a cornercorner with one Ca(1)O4 tetrahedra,  a cornercorner with one Ca(6)O4 tetrahedra, corners with two equivalent Ca(4)O4 tetrahedra, corners with two equivalent Bi(6)O4 tetrahedra,  an edgeedge with one Ca(5)O6 octahedra,  an edgeedge with one Bi(3)O6 octahedra, and edges with four equivalent Bi(5)O6 octahedra. In the sixth Bi site, Bi(6) is bonded to one O(6) and three equivalent O(11) atoms to form BiO4 tetrahedra that share corners with three equivalent Ca(5)O6 octahedra, corners with three equivalent Bi(1)O6 octahedra, and corners with six equivalent Bi(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(5), and two equivalent Bi(1) atoms to form distorted OCa2Bi2 trigonal pyramids that share corners with two equivalent O(1)Ca2Bi2 trigonal pyramids, corners with three equivalent O(11)CaBi3 trigonal pyramids, and edges with two equivalent O(1)Ca2Bi2 trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(2) and three equivalent Bi(1) atoms. In the third O site, O(3) is bonded to one Ca(2), one Ca(3), and two equivalent Bi(2) atoms to form a mixture of distorted corner and edge-sharing OCa2Bi2 trigonal pyramids. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Ca(3), one Bi(4), and two equivalent Bi(1) atoms. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(4) and three equivalent Bi(2) atoms. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Bi(6) and three equivalent Bi(1) atoms. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Ca(4), one Bi(3), and two equivalent Bi(5) atoms. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Ca(6), one Bi(3), and two equivalent Bi(2) atoms. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1) and three equivalent Bi(5) atoms. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Bi(4) and three equivalent Bi(2) atoms. In the eleventh O site, O(11) is bonded to one Ca(5), one Bi(6), and two equivalent Bi(5) atoms to form distorted OCaBi3 trigonal pyramids that share corners with two equivalent O(11)CaBi3 trigonal pyramids, corners with three equivalent O(1)Ca2Bi2 trigonal pyramids,  an edgeedge with one O(12)CaBi3 trigonal pyramid, and edges with two equivalent O(11)CaBi3 trigonal pyramids. In the twelfth O site, O(12) is bonded to one Ca(6) and three equivalent Bi(5) atoms to form distorted edge-sharing OCaBi3 trigonal pyramids.
CaBi2O4 is Spinel-like structured and crystallizes in the trigonal P3m1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(9) and three equivalent O(1) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(5)O6 octahedra, corners with three equivalent Bi(5)O6 octahedra, and corners with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. The Ca(1)-O(9) bond length is 2.33 Å. All Ca(1)-O(1) bond lengths are 2.34 Å. In the second Ca site, Ca(2) is bonded to one O(2) and three equivalent O(3) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra, corners with three equivalent Bi(1)O6 octahedra, and corners with six equivalent Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. The Ca(2)-O(2) bond length is 2.36 Å. All Ca(2)-O(3) bond lengths are 2.32 Å. In the third Ca site, Ca(3) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form CaO6 octahedra that share corners with three equivalent Ca(2)O4 tetrahedra, corners with three equivalent Bi(4)O4 tetrahedra, edges with three equivalent Bi(1)O6 octahedra, and edges with three equivalent Bi(2)O6 octahedra. All Ca(3)-O(3) bond lengths are 2.41 Å. All Ca(3)-O(4) bond lengths are 2.42 Å. In the fourth Ca site, Ca(4) is bonded to one O(5) and three equivalent O(7) atoms to form CaO4 tetrahedra that share corners with three equivalent Bi(2)O6 octahedra, corners with three equivalent Bi(3)O6 octahedra, and corners with six equivalent Bi(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-60°. The Ca(4)-O(5) bond length is 2.33 Å. All Ca(4)-O(7) bond lengths are 2.30 Å. In the fifth Ca site, Ca(5) is bonded to three equivalent O(1) and three equivalent O(11) atoms to form CaO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Bi(6)O4 tetrahedra, edges with three equivalent Bi(1)O6 octahedra, and edges with three equivalent Bi(5)O6 octahedra. All Ca(5)-O(1) bond lengths are 2.40 Å. All Ca(5)-O(11) bond lengths are 2.42 Å. In the sixth Ca site, Ca(6) is bonded to one O(12) and three equivalent O(8) atoms to form CaO4 tetrahedra that share corners with three equivalent Bi(3)O6 octahedra, corners with three equivalent Bi(5)O6 octahedra, and corners with six equivalent Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-59°. The Ca(6)-O(12) bond length is 2.29 Å. All Ca(6)-O(8) bond lengths are 2.29 Å. There are six inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(2), one O(6), two equivalent O(1), and two equivalent O(4) atoms to form BiO6 octahedra that share  a cornercorner with one Ca(2)O4 tetrahedra,  a cornercorner with one Bi(6)O4 tetrahedra, corners with two equivalent Ca(1)O4 tetrahedra, corners with two equivalent Bi(4)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Ca(5)O6 octahedra, and edges with four equivalent Bi(1)O6 octahedra. The Bi(1)-O(2) bond length is 2.40 Å. The Bi(1)-O(6) bond length is 2.48 Å. Both Bi(1)-O(1) bond lengths are 2.35 Å. Both Bi(1)-O(4) bond lengths are 2.46 Å. In the second Bi site, Bi(2) is bonded to one O(10), one O(5), two equivalent O(3), and two equivalent O(8) atoms to form BiO6 octahedra that share  a cornercorner with one Ca(4)O4 tetrahedra,  a cornercorner with one Bi(4)O4 tetrahedra, corners with two equivalent Ca(2)O4 tetrahedra, corners with two equivalent Ca(6)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Bi(3)O6 octahedra, and edges with four equivalent Bi(2)O6 octahedra. The Bi(2)-O(10) bond length is 2.48 Å. The Bi(2)-O(5) bond length is 2.40 Å. Both Bi(2)-O(3) bond lengths are 2.35 Å. Both Bi(2)-O(8) bond lengths are 2.48 Å. In the third Bi site, Bi(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form BiO6 octahedra that share corners with three equivalent Ca(4)O4 tetrahedra, corners with three equivalent Ca(6)O4 tetrahedra, edges with three equivalent Bi(2)O6 octahedra, and edges with three equivalent Bi(5)O6 octahedra. All Bi(3)-O(7) bond lengths are 2.50 Å. All Bi(3)-O(8) bond lengths are 2.36 Å. In the fourth Bi site, Bi(4) is bonded to one O(10) and three equivalent O(4) atoms to form BiO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra, corners with three equivalent Bi(2)O6 octahedra, and corners with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-59°. The Bi(4)-O(10) bond length is 2.26 Å. All Bi(4)-O(4) bond lengths are 2.27 Å. In the fifth Bi site, Bi(5) is bonded to one O(12), one O(9), two equivalent O(11), and two equivalent O(7) atoms to form BiO6 octahedra that share  a cornercorner with one Ca(1)O4 tetrahedra,  a cornercorner with one Ca(6)O4 tetrahedra, corners with two equivalent Ca(4)O4 tetrahedra, corners with two equivalent Bi(6)O4 tetrahedra,  an edgeedge with one Ca(5)O6 octahedra,  an edgeedge with one Bi(3)O6 octahedra, and edges with four equivalent Bi(5)O6 octahedra. The Bi(5)-O(12) bond length is 2.43 Å. The Bi(5)-O(9) bond length is 2.42 Å. Both Bi(5)-O(11) bond lengths are 2.45 Å. Both Bi(5)-O(7) bond lengths are 2.39 Å. In the sixth Bi site, Bi(6) is bonded to one O(6) and three equivalent O(11) atoms to form BiO4 tetrahedra that share corners with three equivalent Ca(5)O6 octahedra, corners with three equivalent Bi(1)O6 octahedra, and corners with six equivalent Bi(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. The Bi(6)-O(6) bond length is 2.26 Å. All Bi(6)-O(11) bond lengths are 2.27 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(5), and two equivalent Bi(1) atoms to form distorted OCa2Bi2 trigonal pyramids that share corners with two equivalent O(1)Ca2Bi2 trigonal pyramids, corners with three equivalent O(11)CaBi3 trigonal pyramids, and edges with two equivalent O(1)Ca2Bi2 trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(2) and three equivalent Bi(1) atoms. In the third O site, O(3) is bonded to one Ca(2), one Ca(3), and two equivalent Bi(2) atoms to form a mixture of distorted corner and edge-sharing OCa2Bi2 trigonal pyramids. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Ca(3), one Bi(4), and two equivalent Bi(1) atoms. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(4) and three equivalent Bi(2) atoms. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Bi(6) and three equivalent Bi(1) atoms. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Ca(4), one Bi(3), and two equivalent Bi(5) atoms. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Ca(6), one Bi(3), and two equivalent Bi(2) atoms. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1) and three equivalent Bi(5) atoms. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Bi(4) and three equivalent Bi(2) atoms. In the eleventh O site, O(11) is bonded to one Ca(5), one Bi(6), and two equivalent Bi(5) atoms to form distorted OCaBi3 trigonal pyramids that share corners with two equivalent O(11)CaBi3 trigonal pyramids, corners with three equivalent O(1)Ca2Bi2 trigonal pyramids,  an edgeedge with one O(12)CaBi3 trigonal pyramid, and edges with two equivalent O(11)CaBi3 trigonal pyramids. In the twelfth O site, O(12) is bonded to one Ca(6) and three equivalent Bi(5) atoms to form distorted edge-sharing OCaBi3 trigonal pyramids.