Ca2Bi3O8 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2/m space group. Ca(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), and four equivalent O(3) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form edge-sharing BiO6 octahedra. In the second Bi site, Bi(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form edge-sharing BiO6 octahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1) and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Bi(1), and two equivalent Bi(2) atoms. In the third O site, O(3) is bonded to two equivalent Ca(1), one Bi(1), and one Bi(2) atom to form a mixture of edge and corner-sharing OCa2Bi2 tetrahedra.
Ca2Bi3O8 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2/m space group. Ca(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), and four equivalent O(3) atoms. The Ca(1)-O(1) bond length is 2.43 Å. The Ca(1)-O(2) bond length is 2.52 Å. There are two shorter (2.37 Å) and two longer (2.51 Å) Ca(1)-O(3) bond lengths. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form edge-sharing BiO6 octahedra. Both Bi(1)-O(2) bond lengths are 2.41 Å. All Bi(1)-O(3) bond lengths are 2.38 Å. In the second Bi site, Bi(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form edge-sharing BiO6 octahedra. Both Bi(2)-O(1) bond lengths are 2.20 Å. Both Bi(2)-O(2) bond lengths are 2.30 Å. Both Bi(2)-O(3) bond lengths are 2.19 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1) and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Bi(1), and two equivalent Bi(2) atoms. In the third O site, O(3) is bonded to two equivalent Ca(1), one Bi(1), and one Bi(2) atom to form a mixture of edge and corner-sharing OCa2Bi2 tetrahedra.