MgNbOF3 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to two equivalent O(1), two equivalent F(1), and two equivalent F(2) atoms to form MgO2F4 octahedra that share corners with two equivalent Nb(1)O2F4 octahedra, corners with four equivalent Mg(1)O2F4 octahedra, and edges with four equivalent Nb(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. Nb(1) is bonded to two equivalent O(1), two equivalent F(1), and two equivalent F(2) atoms to form NbO2F4 octahedra that share corners with two equivalent Mg(1)O2F4 octahedra, corners with four equivalent Nb(1)O2F4 octahedra, and edges with four equivalent Mg(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. O(1) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Nb(1) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a linear geometry to one Mg(1) and one Nb(1) atom. In the second F site, F(2) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Nb(1) atoms.
MgNbOF3 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to two equivalent O(1), two equivalent F(1), and two equivalent F(2) atoms to form MgO2F4 octahedra that share corners with two equivalent Nb(1)O2F4 octahedra, corners with four equivalent Mg(1)O2F4 octahedra, and edges with four equivalent Nb(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. Both Mg(1)-O(1) bond lengths are 2.26 Å. Both Mg(1)-F(1) bond lengths are 1.92 Å. Both Mg(1)-F(2) bond lengths are 2.08 Å. Nb(1) is bonded to two equivalent O(1), two equivalent F(1), and two equivalent F(2) atoms to form NbO2F4 octahedra that share corners with two equivalent Mg(1)O2F4 octahedra, corners with four equivalent Nb(1)O2F4 octahedra, and edges with four equivalent Mg(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. Both Nb(1)-O(1) bond lengths are 2.08 Å. Both Nb(1)-F(1) bond lengths are 2.11 Å. Both Nb(1)-F(2) bond lengths are 2.26 Å. O(1) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Nb(1) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a linear geometry to one Mg(1) and one Nb(1) atom. In the second F site, F(2) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Nb(1) atoms.