MgMn2(SeO3)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a distorted square co-planar geometry to one O(11), one O(6), one O(7), and one O(9) atom. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted octahedral geometry to one O(1), one O(11), one O(3), one O(6), one O(7), and one O(9) atom. In the second Mn site, Mn(2) is bonded in an octahedral geometry to one O(10), one O(12), one O(2), one O(4), one O(5), and one O(8) atom. There are three inequivalent Se sites. In the first Se site, Se(1,4) is bonded in a distorted trigonal non-coplanar geometry to one O(12), one O(3), and one O(8) atom. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(11), one O(4), and one O(7) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one O(2), one O(6), and one O(9) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(1,4) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Mn(2) and one Se(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(1,4) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Mn(2) and one Se(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1,4) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Se(3) atom. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Mn(1), and one Se(2) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1,4) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Mn(1), and one Se(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1,4) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Se(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1,4) atom.
MgMn2(SeO3)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a distorted square co-planar geometry to one O(11), one O(6), one O(7), and one O(9) atom. The Mg(1)-O(11) bond length is 2.02 Å. The Mg(1)-O(6) bond length is 2.02 Å. The Mg(1)-O(7) bond length is 2.15 Å. The Mg(1)-O(9) bond length is 2.15 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted octahedral geometry to one O(1), one O(11), one O(3), one O(6), one O(7), and one O(9) atom. The Mn(1)-O(1) bond length is 1.94 Å. The Mn(1)-O(11) bond length is 2.40 Å. The Mn(1)-O(3) bond length is 1.94 Å. The Mn(1)-O(6) bond length is 2.40 Å. The Mn(1)-O(7) bond length is 1.97 Å. The Mn(1)-O(9) bond length is 1.97 Å. In the second Mn site, Mn(2) is bonded in an octahedral geometry to one O(10), one O(12), one O(2), one O(4), one O(5), and one O(8) atom. The Mn(2)-O(10) bond length is 1.95 Å. The Mn(2)-O(12) bond length is 1.99 Å. The Mn(2)-O(2) bond length is 2.28 Å. The Mn(2)-O(4) bond length is 2.28 Å. The Mn(2)-O(5) bond length is 1.99 Å. The Mn(2)-O(8) bond length is 1.95 Å. There are three inequivalent Se sites. In the first Se site, Se(1,4) is bonded in a distorted trigonal non-coplanar geometry to one O(12), one O(3), and one O(8) atom. The Se(1,4)-O(12) bond length is 1.72 Å. The Se(1,4)-O(3) bond length is 1.74 Å. The Se(1,4)-O(8) bond length is 1.74 Å. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(11), one O(4), and one O(7) atom. The Se(2)-O(11) bond length is 1.72 Å. The Se(2)-O(4) bond length is 1.70 Å. The Se(2)-O(7) bond length is 1.83 Å. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one O(2), one O(6), and one O(9) atom. The Se(3)-O(2) bond length is 1.70 Å. The Se(3)-O(6) bond length is 1.72 Å. The Se(3)-O(9) bond length is 1.83 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(1,4) atom. The O(1)-Se(1,4) bond length is 1.74 Å. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Mn(2) and one Se(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(1,4) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Mn(2) and one Se(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1,4) atom. The O(5)-Se(1,4) bond length is 1.72 Å. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Se(3) atom. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Mn(1), and one Se(2) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1,4) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Mn(1), and one Se(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1,4) atom. The O(10)-Se(1,4) bond length is 1.74 Å. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Se(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1,4) atom.