FeNi3(Mo3N)2 crystallizes in the monoclinic P2_1 space group. There are six inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a distorted bent 150 degrees geometry to one Fe(1), one Ni(2), two equivalent Ni(1), two equivalent Ni(3), and two equivalent N(1) atoms. In the second Mo site, Mo(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Fe(1), one Ni(1), one Ni(3), two equivalent Ni(2), and two equivalent N(2) atoms. In the third Mo site, Mo(3) is bonded in a distorted bent 150 degrees geometry to one Fe(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), one N(1), and one N(2) atom. In the fourth Mo site, Mo(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Fe(1), one Ni(1), one Ni(2), two equivalent Ni(3), one N(1), and one N(2) atom. In the fifth Mo site, Mo(5) is bonded in a distorted bent 150 degrees geometry to two equivalent Fe(1), one Ni(1), one Ni(2), two equivalent Ni(3), one N(1), and one N(2) atom. In the sixth Mo site, Mo(6) is bonded in a bent 150 degrees geometry to one Fe(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), one N(1), and one N(2) atom. Fe(1) is bonded to one Mo(1), one Mo(3), one Mo(6), two equivalent Mo(2), two equivalent Mo(4), two equivalent Mo(5), one Ni(2), and two equivalent Ni(3) atoms to form FeNi3Mo9 cuboctahedra that share corners with two equivalent Fe(1)Ni3Mo9 cuboctahedra, corners with four equivalent Ni(3)Fe2NiMo9 cuboctahedra, corners with four equivalent Ni(1)Ni3Mo9 cuboctahedra, corners with five equivalent Ni(2)FeNi2Mo9 cuboctahedra,  an edgeedge with one N(1)Mo6 octahedra, edges with two equivalent N(2)Mo6 octahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with four equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with two equivalent N(1)Mo6 octahedra, and faces with two equivalent N(2)Mo6 octahedra. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one Mo(2), one Mo(4), one Mo(5), two equivalent Mo(1), two equivalent Mo(3), two equivalent Mo(6), one Ni(3), and two equivalent Ni(2) atoms to form NiNi3Mo9 cuboctahedra that share corners with two equivalent Ni(1)Ni3Mo9 cuboctahedra, corners with four equivalent Fe(1)Ni3Mo9 cuboctahedra, corners with four equivalent Ni(2)FeNi2Mo9 cuboctahedra, corners with five equivalent Ni(3)Fe2NiMo9 cuboctahedra,  an edgeedge with one N(2)Mo6 octahedra, edges with two equivalent N(1)Mo6 octahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with four equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent N(1)Mo6 octahedra, and faces with two equivalent N(2)Mo6 octahedra. In the second Ni site, Ni(2) is bonded to one Mo(1), one Mo(4), one Mo(5), two equivalent Mo(2), two equivalent Mo(3), two equivalent Mo(6), one Fe(1), and two equivalent Ni(1) atoms to form NiFeNi2Mo9 cuboctahedra that share corners with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, corners with four equivalent Ni(3)Fe2NiMo9 cuboctahedra, corners with four equivalent Ni(1)Ni3Mo9 cuboctahedra, corners with five equivalent Fe(1)Ni3Mo9 cuboctahedra,  an edgeedge with one N(1)Mo6 octahedra, edges with two equivalent N(2)Mo6 octahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with four equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent N(1)Mo6 octahedra, and faces with two equivalent N(2)Mo6 octahedra. In the third Ni site, Ni(3) is bonded to one Mo(2), one Mo(3), one Mo(6), two equivalent Mo(1), two equivalent Mo(4), two equivalent Mo(5), two equivalent Fe(1), and one Ni(1) atom to form NiFe2NiMo9 cuboctahedra that share corners with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, corners with four equivalent Fe(1)Ni3Mo9 cuboctahedra, corners with four equivalent Ni(2)FeNi2Mo9 cuboctahedra, corners with five equivalent Ni(1)Ni3Mo9 cuboctahedra,  an edgeedge with one N(2)Mo6 octahedra, edges with two equivalent N(1)Mo6 octahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with four equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with two equivalent N(1)Mo6 octahedra, and faces with two equivalent N(2)Mo6 octahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Mo(3), one Mo(4), one Mo(5), one Mo(6), and two equivalent Mo(1) atoms to form distorted NMo6 octahedra that share corners with two equivalent N(1)Mo6 octahedra, corners with four equivalent N(2)Mo6 octahedra,  an edgeedge with one Fe(1)Ni3Mo9 cuboctahedra,  an edgeedge with one Ni(2)FeNi2Mo9 cuboctahedra, edges with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, edges with two equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, and faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra. The corner-sharing octahedral tilt angles are 25°. In the second N site, N(2) is bonded to one Mo(3), one Mo(4), one Mo(5), one Mo(6), and two equivalent Mo(2) atoms to form distorted NMo6 octahedra that share corners with two equivalent N(2)Mo6 octahedra, corners with four equivalent N(1)Mo6 octahedra,  an edgeedge with one Ni(3)Fe2NiMo9 cuboctahedra,  an edgeedge with one Ni(1)Ni3Mo9 cuboctahedra, edges with two equivalent Fe(1)Ni3Mo9 cuboctahedra, edges with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, and faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra. The corner-sharing octahedral tilt angles are 25°.
FeNi3(Mo3N)2 crystallizes in the monoclinic P2_1 space group. There are six inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a distorted bent 150 degrees geometry to one Fe(1), one Ni(2), two equivalent Ni(1), two equivalent Ni(3), and two equivalent N(1) atoms. The Mo(1)-Fe(1) bond length is 2.71 Å. The Mo(1)-Ni(2) bond length is 2.75 Å. There is one shorter (2.77 Å) and one longer (2.82 Å) Mo(1)-Ni(1) bond length. There is one shorter (2.75 Å) and one longer (2.85 Å) Mo(1)-Ni(3) bond length. Both Mo(1)-N(1) bond lengths are 2.09 Å. In the second Mo site, Mo(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Fe(1), one Ni(1), one Ni(3), two equivalent Ni(2), and two equivalent N(2) atoms. There is one shorter (2.75 Å) and one longer (2.88 Å) Mo(2)-Fe(1) bond length. The Mo(2)-Ni(1) bond length is 2.74 Å. The Mo(2)-Ni(3) bond length is 2.79 Å. There is one shorter (2.77 Å) and one longer (2.79 Å) Mo(2)-Ni(2) bond length. Both Mo(2)-N(2) bond lengths are 2.09 Å. In the third Mo site, Mo(3) is bonded in a distorted bent 150 degrees geometry to one Fe(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), one N(1), and one N(2) atom. The Mo(3)-Fe(1) bond length is 2.78 Å. The Mo(3)-Ni(3) bond length is 2.83 Å. There is one shorter (2.74 Å) and one longer (2.83 Å) Mo(3)-Ni(1) bond length. There is one shorter (2.75 Å) and one longer (2.76 Å) Mo(3)-Ni(2) bond length. The Mo(3)-N(1) bond length is 2.09 Å. The Mo(3)-N(2) bond length is 2.10 Å. In the fourth Mo site, Mo(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Fe(1), one Ni(1), one Ni(2), two equivalent Ni(3), one N(1), and one N(2) atom. There is one shorter (2.69 Å) and one longer (2.86 Å) Mo(4)-Fe(1) bond length. The Mo(4)-Ni(1) bond length is 2.74 Å. The Mo(4)-Ni(2) bond length is 2.80 Å. There is one shorter (2.76 Å) and one longer (2.77 Å) Mo(4)-Ni(3) bond length. The Mo(4)-N(1) bond length is 2.09 Å. The Mo(4)-N(2) bond length is 2.09 Å. In the fifth Mo site, Mo(5) is bonded in a distorted bent 150 degrees geometry to two equivalent Fe(1), one Ni(1), one Ni(2), two equivalent Ni(3), one N(1), and one N(2) atom. There is one shorter (2.69 Å) and one longer (2.78 Å) Mo(5)-Fe(1) bond length. The Mo(5)-Ni(1) bond length is 2.85 Å. The Mo(5)-Ni(2) bond length is 2.76 Å. There is one shorter (2.76 Å) and one longer (2.80 Å) Mo(5)-Ni(3) bond length. The Mo(5)-N(1) bond length is 2.10 Å. The Mo(5)-N(2) bond length is 2.09 Å. In the sixth Mo site, Mo(6) is bonded in a bent 150 degrees geometry to one Fe(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), one N(1), and one N(2) atom. The Mo(6)-Fe(1) bond length is 2.86 Å. The Mo(6)-Ni(3) bond length is 2.76 Å. Both Mo(6)-Ni(1) bond lengths are 2.74 Å. There is one shorter (2.77 Å) and one longer (2.82 Å) Mo(6)-Ni(2) bond length. The Mo(6)-N(1) bond length is 2.08 Å. The Mo(6)-N(2) bond length is 2.10 Å. Fe(1) is bonded to one Mo(1), one Mo(3), one Mo(6), two equivalent Mo(2), two equivalent Mo(4), two equivalent Mo(5), one Ni(2), and two equivalent Ni(3) atoms to form FeNi3Mo9 cuboctahedra that share corners with two equivalent Fe(1)Ni3Mo9 cuboctahedra, corners with four equivalent Ni(3)Fe2NiMo9 cuboctahedra, corners with four equivalent Ni(1)Ni3Mo9 cuboctahedra, corners with five equivalent Ni(2)FeNi2Mo9 cuboctahedra,  an edgeedge with one N(1)Mo6 octahedra, edges with two equivalent N(2)Mo6 octahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with four equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with two equivalent N(1)Mo6 octahedra, and faces with two equivalent N(2)Mo6 octahedra. The Fe(1)-Ni(2) bond length is 2.48 Å. Both Fe(1)-Ni(3) bond lengths are 2.47 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one Mo(2), one Mo(4), one Mo(5), two equivalent Mo(1), two equivalent Mo(3), two equivalent Mo(6), one Ni(3), and two equivalent Ni(2) atoms to form NiNi3Mo9 cuboctahedra that share corners with two equivalent Ni(1)Ni3Mo9 cuboctahedra, corners with four equivalent Fe(1)Ni3Mo9 cuboctahedra, corners with four equivalent Ni(2)FeNi2Mo9 cuboctahedra, corners with five equivalent Ni(3)Fe2NiMo9 cuboctahedra,  an edgeedge with one N(2)Mo6 octahedra, edges with two equivalent N(1)Mo6 octahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with four equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent N(1)Mo6 octahedra, and faces with two equivalent N(2)Mo6 octahedra. The Ni(1)-Ni(3) bond length is 2.49 Å. Both Ni(1)-Ni(2) bond lengths are 2.49 Å. In the second Ni site, Ni(2) is bonded to one Mo(1), one Mo(4), one Mo(5), two equivalent Mo(2), two equivalent Mo(3), two equivalent Mo(6), one Fe(1), and two equivalent Ni(1) atoms to form NiFeNi2Mo9 cuboctahedra that share corners with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, corners with four equivalent Ni(3)Fe2NiMo9 cuboctahedra, corners with four equivalent Ni(1)Ni3Mo9 cuboctahedra, corners with five equivalent Fe(1)Ni3Mo9 cuboctahedra,  an edgeedge with one N(1)Mo6 octahedra, edges with two equivalent N(2)Mo6 octahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with four equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent N(1)Mo6 octahedra, and faces with two equivalent N(2)Mo6 octahedra. In the third Ni site, Ni(3) is bonded to one Mo(2), one Mo(3), one Mo(6), two equivalent Mo(1), two equivalent Mo(4), two equivalent Mo(5), two equivalent Fe(1), and one Ni(1) atom to form NiFe2NiMo9 cuboctahedra that share corners with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, corners with four equivalent Fe(1)Ni3Mo9 cuboctahedra, corners with four equivalent Ni(2)FeNi2Mo9 cuboctahedra, corners with five equivalent Ni(1)Ni3Mo9 cuboctahedra,  an edgeedge with one N(2)Mo6 octahedra, edges with two equivalent N(1)Mo6 octahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with four equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with two equivalent N(1)Mo6 octahedra, and faces with two equivalent N(2)Mo6 octahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Mo(3), one Mo(4), one Mo(5), one Mo(6), and two equivalent Mo(1) atoms to form distorted NMo6 octahedra that share corners with two equivalent N(1)Mo6 octahedra, corners with four equivalent N(2)Mo6 octahedra,  an edgeedge with one Fe(1)Ni3Mo9 cuboctahedra,  an edgeedge with one Ni(2)FeNi2Mo9 cuboctahedra, edges with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, edges with two equivalent Ni(1)Ni3Mo9 cuboctahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, and faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra. The corner-sharing octahedral tilt angles are 25°. In the second N site, N(2) is bonded to one Mo(3), one Mo(4), one Mo(5), one Mo(6), and two equivalent Mo(2) atoms to form distorted NMo6 octahedra that share corners with two equivalent N(2)Mo6 octahedra, corners with four equivalent N(1)Mo6 octahedra,  an edgeedge with one Ni(3)Fe2NiMo9 cuboctahedra,  an edgeedge with one Ni(1)Ni3Mo9 cuboctahedra, edges with two equivalent Fe(1)Ni3Mo9 cuboctahedra, edges with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, faces with two equivalent Fe(1)Ni3Mo9 cuboctahedra, faces with two equivalent Ni(3)Fe2NiMo9 cuboctahedra, faces with two equivalent Ni(2)FeNi2Mo9 cuboctahedra, and faces with two equivalent Ni(1)Ni3Mo9 cuboctahedra. The corner-sharing octahedral tilt angles are 25°.