Mo6Fe6BC crystallizes in the orthorhombic Imma space group. There are three inequivalent Mo sites. In the first Mo site, Mo(3) is bonded in a 8-coordinate geometry to two equivalent Fe(1), two equivalent Fe(3), two equivalent Fe(4), and two equivalent B(1) atoms. In the second Mo site, Mo(1) is bonded in a 2-coordinate geometry to one Fe(1), one Fe(2), two equivalent Fe(3), two equivalent Fe(4), one B(1), and one C(1) atom. In the third Mo site, Mo(2) is bonded in a 2-coordinate geometry to two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(4), and two equivalent C(1) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Mo(3), four equivalent Mo(1), two equivalent Fe(3), and four equivalent Fe(4) atoms to form FeFe6Mo6 cuboctahedra that share edges with two equivalent C(1)Mo6 octahedra, edges with four equivalent B(1)Mo6 octahedra, faces with two equivalent Fe(1)Fe6Mo6 cuboctahedra, and faces with four equivalent Fe(2)Fe6Mo6 cuboctahedra. In the second Fe site, Fe(2) is bonded to two equivalent Mo(2), four equivalent Mo(1), two equivalent Fe(4), and four equivalent Fe(3) atoms to form FeFe6Mo6 cuboctahedra that share edges with two equivalent B(1)Mo6 octahedra, edges with four equivalent C(1)Mo6 octahedra, faces with two equivalent Fe(2)Fe6Mo6 cuboctahedra, and faces with four equivalent Fe(1)Fe6Mo6 cuboctahedra. In the third Fe site, Fe(3) is bonded in a distorted q6 geometry to one Mo(2), one Mo(3), four equivalent Mo(1), one Fe(1), one Fe(3), two equivalent Fe(2), and two equivalent Fe(4) atoms. In the fourth Fe site, Fe(4) is bonded in a distorted q6 geometry to one Mo(2), one Mo(3), four equivalent Mo(1), one Fe(2), one Fe(4), two equivalent Fe(1), and two equivalent Fe(3) atoms. B(1) is bonded to two equivalent Mo(3) and four equivalent Mo(1) atoms to form BMo6 octahedra that share corners with two equivalent B(1)Mo6 octahedra, corners with four equivalent C(1)Mo6 octahedra, edges with two equivalent Fe(2)Fe6Mo6 cuboctahedra, and edges with four equivalent Fe(1)Fe6Mo6 cuboctahedra. The corner-sharing octahedral tilt angles range from 48-49°. C(1) is bonded to two equivalent Mo(2) and four equivalent Mo(1) atoms to form CMo6 octahedra that share corners with two equivalent C(1)Mo6 octahedra, corners with four equivalent B(1)Mo6 octahedra, edges with two equivalent Fe(1)Fe6Mo6 cuboctahedra, and edges with four equivalent Fe(2)Fe6Mo6 cuboctahedra. The corner-sharing octahedral tilt angles range from 47-48°.
Mo6Fe6BC crystallizes in the orthorhombic Imma space group. There are three inequivalent Mo sites. In the first Mo site, Mo(3) is bonded in a 8-coordinate geometry to two equivalent Fe(1), two equivalent Fe(3), two equivalent Fe(4), and two equivalent B(1) atoms. Both Mo(3)-Fe(1) bond lengths are 2.72 Å. Both Mo(3)-Fe(3) bond lengths are 2.75 Å. Both Mo(3)-Fe(4) bond lengths are 2.69 Å. Both Mo(3)-B(1) bond lengths are 2.16 Å. In the second Mo site, Mo(1) is bonded in a 2-coordinate geometry to one Fe(1), one Fe(2), two equivalent Fe(3), two equivalent Fe(4), one B(1), and one C(1) atom. The Mo(1)-Fe(1) bond length is 2.74 Å. The Mo(1)-Fe(2) bond length is 2.72 Å. Both Mo(1)-Fe(3) bond lengths are 2.72 Å. There is one shorter (2.71 Å) and one longer (2.75 Å) Mo(1)-Fe(4) bond length. The Mo(1)-B(1) bond length is 2.18 Å. The Mo(1)-C(1) bond length is 2.12 Å. In the third Mo site, Mo(2) is bonded in a 2-coordinate geometry to two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(4), and two equivalent C(1) atoms. Both Mo(2)-Fe(2) bond lengths are 2.74 Å. Both Mo(2)-Fe(3) bond lengths are 2.73 Å. Both Mo(2)-Fe(4) bond lengths are 2.73 Å. Both Mo(2)-C(1) bond lengths are 2.15 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Mo(3), four equivalent Mo(1), two equivalent Fe(3), and four equivalent Fe(4) atoms to form FeFe6Mo6 cuboctahedra that share edges with two equivalent C(1)Mo6 octahedra, edges with four equivalent B(1)Mo6 octahedra, faces with two equivalent Fe(1)Fe6Mo6 cuboctahedra, and faces with four equivalent Fe(2)Fe6Mo6 cuboctahedra. Both Fe(1)-Fe(3) bond lengths are 2.37 Å. All Fe(1)-Fe(4) bond lengths are 2.37 Å. In the second Fe site, Fe(2) is bonded to two equivalent Mo(2), four equivalent Mo(1), two equivalent Fe(4), and four equivalent Fe(3) atoms to form FeFe6Mo6 cuboctahedra that share edges with two equivalent B(1)Mo6 octahedra, edges with four equivalent C(1)Mo6 octahedra, faces with two equivalent Fe(2)Fe6Mo6 cuboctahedra, and faces with four equivalent Fe(1)Fe6Mo6 cuboctahedra. Both Fe(2)-Fe(4) bond lengths are 2.37 Å. All Fe(2)-Fe(3) bond lengths are 2.37 Å. In the third Fe site, Fe(3) is bonded in a distorted q6 geometry to one Mo(2), one Mo(3), four equivalent Mo(1), one Fe(1), one Fe(3), two equivalent Fe(2), and two equivalent Fe(4) atoms. The Fe(3)-Fe(3) bond length is 2.43 Å. Both Fe(3)-Fe(4) bond lengths are 2.42 Å. In the fourth Fe site, Fe(4) is bonded in a distorted q6 geometry to one Mo(2), one Mo(3), four equivalent Mo(1), one Fe(2), one Fe(4), two equivalent Fe(1), and two equivalent Fe(3) atoms. The Fe(4)-Fe(4) bond length is 2.42 Å. B(1) is bonded to two equivalent Mo(3) and four equivalent Mo(1) atoms to form BMo6 octahedra that share corners with two equivalent B(1)Mo6 octahedra, corners with four equivalent C(1)Mo6 octahedra, edges with two equivalent Fe(2)Fe6Mo6 cuboctahedra, and edges with four equivalent Fe(1)Fe6Mo6 cuboctahedra. The corner-sharing octahedral tilt angles range from 48-49°. C(1) is bonded to two equivalent Mo(2) and four equivalent Mo(1) atoms to form CMo6 octahedra that share corners with two equivalent C(1)Mo6 octahedra, corners with four equivalent B(1)Mo6 octahedra, edges with two equivalent Fe(1)Fe6Mo6 cuboctahedra, and edges with four equivalent Fe(2)Fe6Mo6 cuboctahedra. The corner-sharing octahedral tilt angles range from 47-48°.