Fe5C2 crystallizes in the monoclinic P2/c space group. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted bent 150 degrees geometry to one C(1) and one C(2) atom. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to one C(1) and two equivalent C(2) atoms. In the third Fe site, Fe(3) is bonded in a bent 150 degrees geometry to one C(1) and one C(2) atom. In the fourth Fe site, Fe(4) is bonded to two equivalent C(1) and two equivalent C(2) atoms to form distorted edge-sharing FeC4 tetrahedra. In the fifth Fe site, Fe(5) is bonded in a 3-coordinate geometry to one C(2) and two equivalent C(1) atoms. In the sixth Fe site, Fe(6) is bonded to two equivalent C(1) and two equivalent C(2) atoms to form distorted edge-sharing FeC4 tetrahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 7-coordinate geometry to one Fe(1), one Fe(2), one Fe(3), one Fe(4), one Fe(6), and two equivalent Fe(5) atoms. In the second C site, C(2) is bonded in a 7-coordinate geometry to one Fe(1), one Fe(3), one Fe(4), one Fe(5), one Fe(6), and two equivalent Fe(2) atoms.
Fe5C2 crystallizes in the monoclinic P2/c space group. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted bent 150 degrees geometry to one C(1) and one C(2) atom. The Fe(1)-C(1) bond length is 1.97 Å. The Fe(1)-C(2) bond length is 2.01 Å. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to one C(1) and two equivalent C(2) atoms. The Fe(2)-C(1) bond length is 1.96 Å. There is one shorter (1.96 Å) and one longer (2.28 Å) Fe(2)-C(2) bond length. In the third Fe site, Fe(3) is bonded in a bent 150 degrees geometry to one C(1) and one C(2) atom. The Fe(3)-C(1) bond length is 1.99 Å. The Fe(3)-C(2) bond length is 1.98 Å. In the fourth Fe site, Fe(4) is bonded to two equivalent C(1) and two equivalent C(2) atoms to form distorted edge-sharing FeC4 tetrahedra. Both Fe(4)-C(1) bond lengths are 2.02 Å. Both Fe(4)-C(2) bond lengths are 2.04 Å. In the fifth Fe site, Fe(5) is bonded in a 3-coordinate geometry to one C(2) and two equivalent C(1) atoms. The Fe(5)-C(2) bond length is 1.95 Å. There is one shorter (1.93 Å) and one longer (2.24 Å) Fe(5)-C(1) bond length. In the sixth Fe site, Fe(6) is bonded to two equivalent C(1) and two equivalent C(2) atoms to form distorted edge-sharing FeC4 tetrahedra. Both Fe(6)-C(1) bond lengths are 2.04 Å. Both Fe(6)-C(2) bond lengths are 2.01 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 7-coordinate geometry to one Fe(1), one Fe(2), one Fe(3), one Fe(4), one Fe(6), and two equivalent Fe(5) atoms. In the second C site, C(2) is bonded in a 7-coordinate geometry to one Fe(1), one Fe(3), one Fe(4), one Fe(5), one Fe(6), and two equivalent Fe(2) atoms.