NpFe(OF2)3 crystallizes in the monoclinic C2/c space group. Np(1) is bonded to one O(1), two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form distorted NpOF6 pentagonal bipyramids that share corners with four equivalent Fe(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 33-37°. Fe(1) is bonded to two equivalent O(2), two equivalent F(1), and two equivalent F(2) atoms to form FeO2F4 octahedra that share corners with four equivalent Np(1)OF6 pentagonal bipyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Np(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Fe(1) atom. There are three inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to one Np(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a bent 150 degrees geometry to one Np(1) and one Fe(1) atom. In the third F site, F(3) is bonded in a single-bond geometry to one Np(1) atom.
NpFe(OF2)3 crystallizes in the monoclinic C2/c space group. Np(1) is bonded to one O(1), two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form distorted NpOF6 pentagonal bipyramids that share corners with four equivalent Fe(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 33-37°. The Np(1)-O(1) bond length is 1.80 Å. Both Np(1)-F(1) bond lengths are 2.18 Å. Both Np(1)-F(2) bond lengths are 2.12 Å. Both Np(1)-F(3) bond lengths are 2.04 Å. Fe(1) is bonded to two equivalent O(2), two equivalent F(1), and two equivalent F(2) atoms to form FeO2F4 octahedra that share corners with four equivalent Np(1)OF6 pentagonal bipyramids. Both Fe(1)-O(2) bond lengths are 1.66 Å. Both Fe(1)-F(1) bond lengths are 2.07 Å. Both Fe(1)-F(2) bond lengths are 2.21 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Np(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Fe(1) atom. There are three inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to one Np(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a bent 150 degrees geometry to one Np(1) and one Fe(1) atom. In the third F site, F(3) is bonded in a single-bond geometry to one Np(1) atom.