MnSeO3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 38°. In the second Mn site, Mn(2) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 38°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one O(3), one O(5), and one O(6) atom. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(4) atom. There are six inequivalent O sites. In the first O site, O(5) is bonded in a trigonal planar geometry to one Mn(1), one Mn(2), and one Se(1) atom. In the second O site, O(6) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1) atom. In the third O site, O(1) is bonded in a distorted see-saw-like geometry to one Mn(1), two equivalent Mn(2), and one Se(2) atom. In the fourth O site, O(2) is bonded in a trigonal planar geometry to one Mn(1), one Mn(2), and one Se(2) atom. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Mn(1) and one Se(1) atom. In the sixth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Mn(1), one Mn(2), and one Se(2) atom.
MnSeO3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 38°. The Mn(1)-O(1) bond length is 2.42 Å. The Mn(1)-O(2) bond length is 2.14 Å. The Mn(1)-O(4) bond length is 2.17 Å. The Mn(1)-O(5) bond length is 2.19 Å. There is one shorter (2.10 Å) and one longer (2.14 Å) Mn(1)-O(3) bond length. In the second Mn site, Mn(2) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 38°. The Mn(2)-O(2) bond length is 2.15 Å. The Mn(2)-O(4) bond length is 2.15 Å. The Mn(2)-O(5) bond length is 2.21 Å. The Mn(2)-O(6) bond length is 2.09 Å. There is one shorter (2.19 Å) and one longer (2.36 Å) Mn(2)-O(1) bond length. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one O(3), one O(5), and one O(6) atom. The Se(1)-O(3) bond length is 1.72 Å. The Se(1)-O(5) bond length is 1.72 Å. The Se(1)-O(6) bond length is 1.68 Å. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(4) atom. The Se(2)-O(1) bond length is 1.74 Å. The Se(2)-O(2) bond length is 1.71 Å. The Se(2)-O(4) bond length is 1.71 Å. There are six inequivalent O sites. In the first O site, O(5) is bonded in a trigonal planar geometry to one Mn(1), one Mn(2), and one Se(1) atom. In the second O site, O(6) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(1) atom. In the third O site, O(1) is bonded in a distorted see-saw-like geometry to one Mn(1), two equivalent Mn(2), and one Se(2) atom. In the fourth O site, O(2) is bonded in a trigonal planar geometry to one Mn(1), one Mn(2), and one Se(2) atom. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Mn(1) and one Se(1) atom. In the sixth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Mn(1), one Mn(2), and one Se(2) atom.