MgNb3O7F crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent F(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 26°. In the second Nb site, Nb(2) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and one F(1) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Nb(2) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1) and two equivalent Nb(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Nb(1) and two equivalent Nb(2) atoms. F(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Nb(2) atoms.
MgNb3O7F crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent F(1) atoms. The Mg(1)-O(2) bond length is 2.04 Å. Both Mg(1)-O(3) bond lengths are 2.05 Å. Both Mg(1)-F(1) bond lengths are 2.07 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 26°. Both Nb(1)-O(1) bond lengths are 2.21 Å. Both Nb(1)-O(2) bond lengths are 1.99 Å. Both Nb(1)-O(4) bond lengths are 2.05 Å. In the second Nb site, Nb(2) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and one F(1) atom. There is one shorter (1.96 Å) and one longer (2.20 Å) Nb(2)-O(1) bond length. Both Nb(2)-O(3) bond lengths are 2.02 Å. There is one shorter (2.09 Å) and one longer (2.11 Å) Nb(2)-O(4) bond length. The Nb(2)-F(1) bond length is 2.45 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Nb(2) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1) and two equivalent Nb(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Nb(1) and two equivalent Nb(2) atoms. F(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Nb(2) atoms.