FeSeO3F crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent F(1) atoms to form edge-sharing FeO4F2 octahedra. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one Se(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Fe(1) and one Se(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one Se(1) atom. F(1) is bonded in a water-like geometry to two equivalent Fe(1) atoms.
FeSeO3F crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent F(1) atoms to form edge-sharing FeO4F2 octahedra. The Fe(1)-O(1) bond length is 1.97 Å. The Fe(1)-O(3) bond length is 1.98 Å. There is one shorter (2.03 Å) and one longer (2.10 Å) Fe(1)-O(2) bond length. There is one shorter (1.99 Å) and one longer (2.04 Å) Fe(1)-F(1) bond length. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. The Se(1)-O(1) bond length is 1.73 Å. The Se(1)-O(2) bond length is 1.79 Å. The Se(1)-O(3) bond length is 1.72 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one Se(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Fe(1) and one Se(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one Se(1) atom. F(1) is bonded in a water-like geometry to two equivalent Fe(1) atoms.