Mo2Fe4N crystallizes in the tetragonal I-4m2 space group. There are three inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 2-coordinate geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent N(1) atoms. In the second Mo site, Mo(2) is bonded in a 2-coordinate geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent N(1) atoms. In the third Mo site, Mo(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent N(1) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Mo(1), one Mo(3), two equivalent Mo(2), two equivalent Fe(4), three equivalent Fe(2), and three equivalent Fe(3) atoms to form distorted FeFe8Mo4 cuboctahedra that share edges with six equivalent N(1)Fe2Mo4 octahedra and faces with six equivalent Fe(1)Fe8Mo4 cuboctahedra. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to one Mo(1), one Mo(3), two equivalent Mo(2), two equivalent Fe(4), three equivalent Fe(1), and three equivalent Fe(2) atoms. In the third Fe site, Fe(3) is bonded in a 12-coordinate geometry to one Mo(1), one Mo(3), two equivalent Mo(2), two equivalent Fe(4), three equivalent Fe(1), and three equivalent Fe(3) atoms. In the fourth Fe site, Fe(4) is bonded in a distorted bent 120 degrees geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent N(1) atoms. N(1) is bonded to one Mo(1), one Mo(3), two equivalent Mo(2), and two equivalent Fe(4) atoms to form NFe2Mo4 octahedra that share corners with six equivalent N(1)Fe2Mo4 octahedra and edges with six equivalent Fe(1)Fe8Mo4 cuboctahedra. The corner-sharing octahedral tilt angles range from 40-46°.
Mo2Fe4N crystallizes in the tetragonal I-4m2 space group. There are three inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 2-coordinate geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent N(1) atoms. Both Mo(1)-Fe(1) bond lengths are 2.75 Å. Both Mo(1)-Fe(2) bond lengths are 2.74 Å. Both Mo(1)-Fe(3) bond lengths are 2.61 Å. Both Mo(1)-N(1) bond lengths are 2.08 Å. In the second Mo site, Mo(2) is bonded in a 2-coordinate geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent N(1) atoms. Both Mo(2)-Fe(1) bond lengths are 2.73 Å. Both Mo(2)-Fe(2) bond lengths are 2.62 Å. Both Mo(2)-Fe(3) bond lengths are 2.72 Å. Both Mo(2)-N(1) bond lengths are 2.14 Å. In the third Mo site, Mo(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent N(1) atoms. Both Mo(3)-Fe(1) bond lengths are 2.73 Å. Both Mo(3)-Fe(2) bond lengths are 2.63 Å. Both Mo(3)-Fe(3) bond lengths are 2.68 Å. Both Mo(3)-N(1) bond lengths are 2.08 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Mo(1), one Mo(3), two equivalent Mo(2), two equivalent Fe(4), three equivalent Fe(2), and three equivalent Fe(3) atoms to form distorted FeFe8Mo4 cuboctahedra that share edges with six equivalent N(1)Fe2Mo4 octahedra and faces with six equivalent Fe(1)Fe8Mo4 cuboctahedra. Both Fe(1)-Fe(4) bond lengths are 2.75 Å. There is one shorter (2.31 Å) and two longer (2.34 Å) Fe(1)-Fe(2) bond lengths. There are two shorter (2.37 Å) and one longer (2.38 Å) Fe(1)-Fe(3) bond length. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to one Mo(1), one Mo(3), two equivalent Mo(2), two equivalent Fe(4), three equivalent Fe(1), and three equivalent Fe(2) atoms. Both Fe(2)-Fe(4) bond lengths are 2.75 Å. There are two shorter (2.50 Å) and one longer (2.51 Å) Fe(2)-Fe(2) bond length. In the third Fe site, Fe(3) is bonded in a 12-coordinate geometry to one Mo(1), one Mo(3), two equivalent Mo(2), two equivalent Fe(4), three equivalent Fe(1), and three equivalent Fe(3) atoms. Both Fe(3)-Fe(4) bond lengths are 2.58 Å. There is one shorter (2.55 Å) and two longer (2.57 Å) Fe(3)-Fe(3) bond lengths. In the fourth Fe site, Fe(4) is bonded in a distorted bent 120 degrees geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent N(1) atoms. Both Fe(4)-N(1) bond lengths are 2.02 Å. N(1) is bonded to one Mo(1), one Mo(3), two equivalent Mo(2), and two equivalent Fe(4) atoms to form NFe2Mo4 octahedra that share corners with six equivalent N(1)Fe2Mo4 octahedra and edges with six equivalent Fe(1)Fe8Mo4 cuboctahedra. The corner-sharing octahedral tilt angles range from 40-46°.