CaBi2O4 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form distorted CaO6 pentagonal pyramids that share edges with four equivalent Bi(2)O6 octahedra. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(3) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(3) atoms. 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 BiO6 octahedra that share edges with two equivalent Bi(2)O6 octahedra and edges with two equivalent Ca(1)O6 pentagonal pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Bi(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(2), one Bi(1), and two equivalent Bi(2) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Bi(1), and one Bi(2) atom.
CaBi2O4 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form distorted CaO6 pentagonal pyramids that share edges with four equivalent Bi(2)O6 octahedra. Both Ca(1)-O(1) bond lengths are 2.29 Å. All Ca(1)-O(3) bond lengths are 2.51 Å. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(3) atoms. Both Ca(2)-O(2) bond lengths are 2.47 Å. All Ca(2)-O(3) bond lengths are 2.61 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(3) atoms. The Bi(1)-O(1) bond length is 2.49 Å. The Bi(1)-O(2) bond length is 2.30 Å. Both Bi(1)-O(3) bond lengths are 2.23 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 BiO6 octahedra that share edges with two equivalent Bi(2)O6 octahedra and edges with two equivalent Ca(1)O6 pentagonal pyramids. Both Bi(2)-O(1) bond lengths are 2.34 Å. Both Bi(2)-O(2) bond lengths are 2.48 Å. Both Bi(2)-O(3) bond lengths are 2.48 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Bi(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(2), one Bi(1), and two equivalent Bi(2) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Bi(1), and one Bi(2) atom.