Mo6Fe11C5 crystallizes in the monoclinic C2/m space group. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 2-coordinate geometry to one Fe(5), one C(2), and two equivalent C(1) atoms. In the second Mo site, Mo(2) is bonded in a 2-coordinate geometry to one Fe(5) and two equivalent C(1) atoms. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted water-like geometry to one Fe(5) and two equivalent C(1) atoms. In the second Fe site, Fe(2) is bonded in a distorted bent 150 degrees geometry to one Fe(5) and two equivalent C(1) atoms. In the third Fe site, Fe(3) is bonded in a single-bond geometry to one C(2) atom. In the fourth Fe site, Fe(4) is bonded in a bent 150 degrees geometry to two equivalent C(1) atoms. In the fifth Fe site, Fe(5) is bonded to two equivalent Mo(2), four equivalent Mo(1), two equivalent Fe(2), and four equivalent Fe(1) atoms to form FeFe6Mo6 cuboctahedra that share edges with two equivalent C(2)Fe2Mo4 octahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 7-coordinate geometry to one Mo(2), two equivalent Mo(1), one Fe(2), one Fe(4), and two equivalent Fe(1) atoms. In the second C site, C(2) is bonded to four equivalent Mo(1) and two equivalent Fe(3) atoms to form CFe2Mo4 octahedra that share edges with two equivalent Fe(5)Fe6Mo6 cuboctahedra.
Mo6Fe11C5 crystallizes in the monoclinic C2/m space group. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 2-coordinate geometry to one Fe(5), one C(2), and two equivalent C(1) atoms. The Mo(1)-Fe(5) bond length is 2.71 Å. The Mo(1)-C(2) bond length is 2.08 Å. There is one shorter (2.19 Å) and one longer (2.38 Å) Mo(1)-C(1) bond length. In the second Mo site, Mo(2) is bonded in a 2-coordinate geometry to one Fe(5) and two equivalent C(1) atoms. The Mo(2)-Fe(5) bond length is 2.78 Å. Both Mo(2)-C(1) bond lengths are 2.20 Å. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted water-like geometry to one Fe(5) and two equivalent C(1) atoms. The Fe(1)-Fe(5) bond length is 2.48 Å. There is one shorter (1.99 Å) and one longer (2.09 Å) Fe(1)-C(1) bond length. In the second Fe site, Fe(2) is bonded in a distorted bent 150 degrees geometry to one Fe(5) and two equivalent C(1) atoms. The Fe(2)-Fe(5) bond length is 2.49 Å. Both Fe(2)-C(1) bond lengths are 1.94 Å. In the third Fe site, Fe(3) is bonded in a single-bond geometry to one C(2) atom. The Fe(3)-C(2) bond length is 1.93 Å. In the fourth Fe site, Fe(4) is bonded in a bent 150 degrees geometry to two equivalent C(1) atoms. Both Fe(4)-C(1) bond lengths are 1.98 Å. In the fifth Fe site, Fe(5) is bonded to two equivalent Mo(2), four equivalent Mo(1), two equivalent Fe(2), and four equivalent Fe(1) atoms to form FeFe6Mo6 cuboctahedra that share edges with two equivalent C(2)Fe2Mo4 octahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 7-coordinate geometry to one Mo(2), two equivalent Mo(1), one Fe(2), one Fe(4), and two equivalent Fe(1) atoms. In the second C site, C(2) is bonded to four equivalent Mo(1) and two equivalent Fe(3) atoms to form CFe2Mo4 octahedra that share edges with two equivalent Fe(5)Fe6Mo6 cuboctahedra.