FeNi5N4 crystallizes in the orthorhombic Pmmn space group. Fe(1) is bonded in a tetrahedral geometry to two equivalent N(1) and two equivalent N(2) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to one N(1) and two equivalent N(2) atoms. In the second Ni site, Ni(2) is bonded in a bent 120 degrees geometry to two equivalent N(1) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Fe(1), one Ni(2), and two equivalent Ni(1) atoms to form corner-sharing NFeNi3 tetrahedra. In the second N site, N(2) is bonded in a distorted pentagonal planar geometry to one Fe(1) and four equivalent Ni(1) atoms.
FeNi5N4 crystallizes in the orthorhombic Pmmn space group. Fe(1) is bonded in a tetrahedral geometry to two equivalent N(1) and two equivalent N(2) atoms. Both Fe(1)-N(1) bond lengths are 1.77 Å. Both Fe(1)-N(2) bond lengths are 1.85 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to one N(1) and two equivalent N(2) atoms. The Ni(1)-N(1) bond length is 1.81 Å. There is one shorter (1.93 Å) and one longer (1.94 Å) Ni(1)-N(2) bond length. In the second Ni site, Ni(2) is bonded in a bent 120 degrees geometry to two equivalent N(1) atoms. Both Ni(2)-N(1) bond lengths are 1.81 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Fe(1), one Ni(2), and two equivalent Ni(1) atoms to form corner-sharing NFeNi3 tetrahedra. In the second N site, N(2) is bonded in a distorted pentagonal planar geometry to one Fe(1) and four equivalent Ni(1) atoms.