MgCo3BiO8 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share edges with two equivalent Co(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form CoO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. In the second Co site, Co(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form CoO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. In the third Co site, Co(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Co(1), one Co(3), and one Bi(1) atom. In the second O site, O(2) is bonded in a distorted see-saw-like geometry to one Mg(1), one Co(2), one Co(3), and one Bi(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Co(1), one Co(2), and one Co(3) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(2), and one Bi(1) atom.
MgCo3BiO8 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share edges with two equivalent Co(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. Both Mg(1)-O(1) bond lengths are 2.05 Å. Both Mg(1)-O(2) bond lengths are 2.05 Å. Both Mg(1)-O(4) bond lengths are 2.09 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form CoO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. Both Co(1)-O(1) bond lengths are 1.90 Å. Both Co(1)-O(3) bond lengths are 1.90 Å. Both Co(1)-O(4) bond lengths are 1.91 Å. In the second Co site, Co(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form CoO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. Both Co(2)-O(2) bond lengths are 1.92 Å. Both Co(2)-O(3) bond lengths are 1.86 Å. Both Co(2)-O(4) bond lengths are 1.94 Å. In the third Co site, Co(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. Both Co(3)-O(1) bond lengths are 1.94 Å. Both Co(3)-O(2) bond lengths are 1.91 Å. Both Co(3)-O(3) bond lengths are 2.15 Å. Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. Both Bi(1)-O(1) bond lengths are 2.40 Å. Both Bi(1)-O(2) bond lengths are 2.40 Å. Both Bi(1)-O(4) bond lengths are 2.38 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Co(1), one Co(3), and one Bi(1) atom. In the second O site, O(2) is bonded in a distorted see-saw-like geometry to one Mg(1), one Co(2), one Co(3), and one Bi(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Co(1), one Co(2), and one Co(3) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(2), and one Bi(1) atom.