MgV4Tl4(TeO5)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one Tl(2), one O(15), one O(17), one O(2), and one O(9) atom. There are four inequivalent V sites. In the first V site, V(1) is bonded in a 5-coordinate geometry to one O(12), one O(14), one O(19), one O(3), one O(5), and one O(6) atom. In the second V site, V(2) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(20), one O(8), and one O(9) atom. In the third V site, V(3) is bonded to one O(13), one O(18), one O(3), one O(4), one O(6), and one O(7) atom to form distorted VO6 octahedra that share  a cornercorner with one Te(4)O5 square pyramid. In the fourth V site, V(4) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(15), one O(16), one O(17), and one O(9) atom. There are four inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(17), one O(18), one O(2), and one O(3) atom. In the second Tl site, Tl(2) is bonded in a 5-coordinate geometry to one Mg(1), one O(16), one O(19), one O(6), and one O(7) atom. In the third Tl site, Tl(3) is bonded in a distorted single-bond geometry to one O(12) atom. In the fourth Tl site, Tl(4) is bonded in a distorted bent 120 degrees geometry to one O(12) and one O(13) atom. There are four inequivalent Te sites. In the first Te site, Te(1) is bonded in a 3-coordinate geometry to one O(15), one O(2), and one O(7) atom. In the second Te site, Te(2) is bonded in a 5-coordinate geometry to one O(16), one O(19), one O(20), one O(4), and one O(7) atom. In the third Te site, Te(3) is bonded in a 3-coordinate geometry to one O(10), one O(12), and one O(13) atom. In the fourth Te site, Te(4) is bonded to one O(10), one O(11), one O(14), one O(17), and one O(18) atom to form distorted TeO5 square pyramids that share  a cornercorner with one V(3)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one V(2), one V(4), and one Tl(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Mg(1), one Tl(1), and one Te(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one V(1), one V(3), and one Tl(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one V(3) and one Te(2) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one V(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one V(1), one V(3), and one Tl(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one V(3), one Tl(2), one Te(1), and one Te(2) atom. In the eighth O site, O(8) is bonded in a single-bond geometry to one V(2) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Mg(1), one V(2), and one V(4) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one V(4), one Te(3), and one Te(4) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one V(2), one Tl(1), and one Te(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one V(1), one Tl(3), one Tl(4), and one Te(3) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one V(3), one Tl(4), and one Te(3) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one V(1) and one Te(4) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Mg(1), one V(4), and one Te(1) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one V(4), one Tl(2), and one Te(2) atom. In the seventeenth O site, O(17) is bonded in a 3-coordinate geometry to one Mg(1), one V(4), one Tl(1), and one Te(4) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one V(3), one Tl(1), and one Te(4) atom. In the nineteenth O site, O(19) is bonded in a 3-coordinate geometry to one V(1), one Tl(2), and one Te(2) atom. In the twentieth O site, O(20) is bonded in a distorted bent 120 degrees geometry to one V(2) and one Te(2) atom.
MgV4Tl4(TeO5)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one Tl(2), one O(15), one O(17), one O(2), and one O(9) atom. The Mg(1)-Tl(2) bond length is 2.80 Å. The Mg(1)-O(15) bond length is 2.31 Å. The Mg(1)-O(17) bond length is 2.09 Å. The Mg(1)-O(2) bond length is 2.07 Å. The Mg(1)-O(9) bond length is 1.93 Å. There are four inequivalent V sites. In the first V site, V(1) is bonded in a 5-coordinate geometry to one O(12), one O(14), one O(19), one O(3), one O(5), and one O(6) atom. The V(1)-O(12) bond length is 2.69 Å. The V(1)-O(14) bond length is 1.96 Å. The V(1)-O(19) bond length is 2.05 Å. The V(1)-O(3) bond length is 1.75 Å. The V(1)-O(5) bond length is 1.67 Å. The V(1)-O(6) bond length is 1.92 Å. In the second V site, V(2) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(20), one O(8), and one O(9) atom. The V(2)-O(1) bond length is 1.82 Å. The V(2)-O(11) bond length is 1.94 Å. The V(2)-O(20) bond length is 1.97 Å. The V(2)-O(8) bond length is 1.67 Å. The V(2)-O(9) bond length is 1.86 Å. In the third V site, V(3) is bonded to one O(13), one O(18), one O(3), one O(4), one O(6), and one O(7) atom to form distorted VO6 octahedra that share  a cornercorner with one Te(4)O5 square pyramid. The V(3)-O(13) bond length is 1.98 Å. The V(3)-O(18) bond length is 1.73 Å. The V(3)-O(3) bond length is 2.02 Å. The V(3)-O(4) bond length is 2.18 Å. The V(3)-O(6) bond length is 1.93 Å. The V(3)-O(7) bond length is 2.15 Å. In the fourth V site, V(4) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(15), one O(16), one O(17), and one O(9) atom. The V(4)-O(1) bond length is 1.90 Å. The V(4)-O(10) bond length is 2.02 Å. The V(4)-O(15) bond length is 2.08 Å. The V(4)-O(16) bond length is 1.72 Å. The V(4)-O(17) bond length is 2.36 Å. The V(4)-O(9) bond length is 2.03 Å. There are four inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(17), one O(18), one O(2), and one O(3) atom. The Tl(1)-O(1) bond length is 2.90 Å. The Tl(1)-O(11) bond length is 2.82 Å. The Tl(1)-O(17) bond length is 2.94 Å. The Tl(1)-O(18) bond length is 2.88 Å. The Tl(1)-O(2) bond length is 2.92 Å. The Tl(1)-O(3) bond length is 2.88 Å. In the second Tl site, Tl(2) is bonded in a 5-coordinate geometry to one Mg(1), one O(16), one O(19), one O(6), and one O(7) atom. The Tl(2)-O(16) bond length is 2.48 Å. The Tl(2)-O(19) bond length is 2.58 Å. The Tl(2)-O(6) bond length is 2.40 Å. The Tl(2)-O(7) bond length is 2.86 Å. In the third Tl site, Tl(3) is bonded in a distorted single-bond geometry to one O(12) atom. The Tl(3)-O(12) bond length is 2.58 Å. In the fourth Tl site, Tl(4) is bonded in a distorted bent 120 degrees geometry to one O(12) and one O(13) atom. The Tl(4)-O(12) bond length is 2.70 Å. The Tl(4)-O(13) bond length is 2.73 Å. There are four inequivalent Te sites. In the first Te site, Te(1) is bonded in a 3-coordinate geometry to one O(15), one O(2), and one O(7) atom. The Te(1)-O(15) bond length is 1.98 Å. The Te(1)-O(2) bond length is 1.91 Å. The Te(1)-O(7) bond length is 1.93 Å. In the second Te site, Te(2) is bonded in a 5-coordinate geometry to one O(16), one O(19), one O(20), one O(4), and one O(7) atom. The Te(2)-O(16) bond length is 2.62 Å. The Te(2)-O(19) bond length is 1.95 Å. The Te(2)-O(20) bond length is 1.95 Å. The Te(2)-O(4) bond length is 1.89 Å. The Te(2)-O(7) bond length is 2.50 Å. In the third Te site, Te(3) is bonded in a 3-coordinate geometry to one O(10), one O(12), and one O(13) atom. The Te(3)-O(10) bond length is 1.95 Å. The Te(3)-O(12) bond length is 1.87 Å. The Te(3)-O(13) bond length is 1.93 Å. In the fourth Te site, Te(4) is bonded to one O(10), one O(11), one O(14), one O(17), and one O(18) atom to form distorted TeO5 square pyramids that share  a cornercorner with one V(3)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. The Te(4)-O(10) bond length is 2.58 Å. The Te(4)-O(11) bond length is 1.96 Å. The Te(4)-O(14) bond length is 1.96 Å. The Te(4)-O(17) bond length is 1.91 Å. The Te(4)-O(18) bond length is 2.45 Å. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one V(2), one V(4), and one Tl(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Mg(1), one Tl(1), and one Te(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one V(1), one V(3), and one Tl(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one V(3) and one Te(2) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one V(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one V(1), one V(3), and one Tl(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one V(3), one Tl(2), one Te(1), and one Te(2) atom. In the eighth O site, O(8) is bonded in a single-bond geometry to one V(2) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Mg(1), one V(2), and one V(4) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one V(4), one Te(3), and one Te(4) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one V(2), one Tl(1), and one Te(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one V(1), one Tl(3), one Tl(4), and one Te(3) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one V(3), one Tl(4), and one Te(3) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one V(1) and one Te(4) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Mg(1), one V(4), and one Te(1) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one V(4), one Tl(2), and one Te(2) atom. In the seventeenth O site, O(17) is bonded in a 3-coordinate geometry to one Mg(1), one V(4), one Tl(1), and one Te(4) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one V(3), one Tl(1), and one Te(4) atom. In the nineteenth O site, O(19) is bonded in a 3-coordinate geometry to one V(1), one Tl(2), and one Te(2) atom. In the twentieth O site, O(20) is bonded in a distorted bent 120 degrees geometry to one V(2) and one Te(2) atom.