MgBi4(WO6)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(12), one O(4), one O(7), one O(8), and one O(9) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one W(2)O6 octahedra. The corner-sharing octahedral tilt angles are 19°. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(10), one O(11), one O(2), one O(5), and one O(6) atom to form corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 15-23°. In the second W site, W(2) is bonded to one O(10), one O(11), one O(3), one O(4), one O(5), and one O(6) atom to form WO6 octahedra that share corners with four equivalent W(1)O6 octahedra and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 15-23°. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(7), one O(8), and one O(9) atom. In the second Bi site, Bi(2) is bonded in a 3-coordinate geometry to one O(1), one O(12), and one O(3) atom. In the third Bi site, Bi(3) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(3), one O(7), one O(8), and one O(9) atom. In the fourth Bi site, Bi(4) is bonded in a 5-coordinate geometry to one O(12), one O(2), one O(4), one O(7), and one O(9) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one W(1), one Bi(2), and one Bi(3) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one W(1), one Bi(1), and one Bi(4) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one W(2), one Bi(2), and one Bi(3) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one W(2), one Bi(1), and one Bi(4) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one W(1) and one W(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one W(1) and one W(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Mg(1), one Bi(1), one Bi(3), and one Bi(4) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Mg(1), one Bi(1), and one Bi(3) atom. In the ninth O site, O(9) is bonded in a distorted tetrahedral geometry to one Mg(1), one Bi(1), one Bi(3), and one Bi(4) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one W(1) and one W(2) atom. In the eleventh O site, O(11) is bonded in a distorted linear geometry to one W(1) and one W(2) atom. In the twelfth O site, O(12) is bonded in a distorted see-saw-like geometry to one Mg(1), one Bi(2), one Bi(3), and one Bi(4) atom.
MgBi4(WO6)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(12), one O(4), one O(7), one O(8), and one O(9) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one W(2)O6 octahedra. The corner-sharing octahedral tilt angles are 19°. The Mg(1)-O(12) bond length is 2.01 Å. The Mg(1)-O(4) bond length is 2.08 Å. The Mg(1)-O(7) bond length is 2.00 Å. The Mg(1)-O(8) bond length is 2.01 Å. The Mg(1)-O(9) bond length is 2.02 Å. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(10), one O(11), one O(2), one O(5), and one O(6) atom to form corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 15-23°. The W(1)-O(1) bond length is 2.06 Å. The W(1)-O(10) bond length is 2.05 Å. The W(1)-O(11) bond length is 1.92 Å. The W(1)-O(2) bond length is 2.05 Å. The W(1)-O(5) bond length is 1.95 Å. The W(1)-O(6) bond length is 2.09 Å. In the second W site, W(2) is bonded to one O(10), one O(11), one O(3), one O(4), one O(5), and one O(6) atom to form WO6 octahedra that share corners with four equivalent W(1)O6 octahedra and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 15-23°. The W(2)-O(10) bond length is 2.00 Å. The W(2)-O(11) bond length is 2.12 Å. The W(2)-O(3) bond length is 2.06 Å. The W(2)-O(4) bond length is 2.06 Å. The W(2)-O(5) bond length is 2.01 Å. The W(2)-O(6) bond length is 1.88 Å. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(7), one O(8), and one O(9) atom. The Bi(1)-O(2) bond length is 2.28 Å. The Bi(1)-O(4) bond length is 2.53 Å. The Bi(1)-O(7) bond length is 2.27 Å. The Bi(1)-O(8) bond length is 2.42 Å. The Bi(1)-O(9) bond length is 2.22 Å. In the second Bi site, Bi(2) is bonded in a 3-coordinate geometry to one O(1), one O(12), and one O(3) atom. The Bi(2)-O(1) bond length is 2.12 Å. The Bi(2)-O(12) bond length is 2.37 Å. The Bi(2)-O(3) bond length is 2.14 Å. In the third Bi site, Bi(3) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(3), one O(7), one O(8), and one O(9) atom. The Bi(3)-O(1) bond length is 2.82 Å. The Bi(3)-O(12) bond length is 2.34 Å. The Bi(3)-O(3) bond length is 2.46 Å. The Bi(3)-O(7) bond length is 2.52 Å. The Bi(3)-O(8) bond length is 2.14 Å. The Bi(3)-O(9) bond length is 2.32 Å. In the fourth Bi site, Bi(4) is bonded in a 5-coordinate geometry to one O(12), one O(2), one O(4), one O(7), and one O(9) atom. The Bi(4)-O(12) bond length is 2.37 Å. The Bi(4)-O(2) bond length is 2.39 Å. The Bi(4)-O(4) bond length is 2.55 Å. The Bi(4)-O(7) bond length is 2.21 Å. The Bi(4)-O(9) bond length is 2.30 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one W(1), one Bi(2), and one Bi(3) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one W(1), one Bi(1), and one Bi(4) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one W(2), one Bi(2), and one Bi(3) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one W(2), one Bi(1), and one Bi(4) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one W(1) and one W(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one W(1) and one W(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Mg(1), one Bi(1), one Bi(3), and one Bi(4) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Mg(1), one Bi(1), and one Bi(3) atom. In the ninth O site, O(9) is bonded in a distorted tetrahedral geometry to one Mg(1), one Bi(1), one Bi(3), and one Bi(4) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one W(1) and one W(2) atom. In the eleventh O site, O(11) is bonded in a distorted linear geometry to one W(1) and one W(2) atom. In the twelfth O site, O(12) is bonded in a distorted see-saw-like geometry to one Mg(1), one Bi(2), one Bi(3), and one Bi(4) atom.