MgSeO4 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra and edges with two equivalent Mg(1)O6 octahedra. Se(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SeO4 tetrahedra that share corners with six equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-55°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Mg(1) and one Se(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mg(1) and one Se(1) atom.
MgSeO4 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra and edges with two equivalent Mg(1)O6 octahedra. Both Mg(1)-O(2) bond lengths are 2.02 Å. All Mg(1)-O(1) bond lengths are 2.14 Å. Se(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SeO4 tetrahedra that share corners with six equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-55°. Both Se(1)-O(1) bond lengths are 1.67 Å. Both Se(1)-O(2) bond lengths are 1.63 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Mg(1) and one Se(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mg(1) and one Se(1) atom.