Fe5SiC crystallizes in the orthorhombic Cmc2_1 space group. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted water-like geometry to one Fe(6), two equivalent Si(1), one C(1), and one C(2) atom. In the second Fe site, Fe(2) is bonded in a distorted water-like geometry to two equivalent Si(1), one C(1), and one C(2) atom. In the third Fe site, Fe(3) is bonded in a distorted linear geometry to two equivalent Si(1), one C(1), and one C(2) atom. In the fourth Fe site, Fe(4) is bonded in a single-bond geometry to one Fe(6), three equivalent Si(1), and one C(1) atom. In the fifth Fe site, Fe(5) is bonded in a single-bond geometry to one Fe(6), three equivalent Si(1), and one C(2) atom. In the sixth Fe site, Fe(6) is bonded in a 10-coordinate geometry to two equivalent Fe(1), two equivalent Fe(4), two equivalent Fe(5), two equivalent Si(1), one C(1), and one C(2) atom. Si(1) is bonded to one Fe(3), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), three equivalent Fe(4), and three equivalent Fe(5) atoms to form a mixture of distorted corner, face, and edge-sharing SiFe12 cuboctahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 7-coordinate geometry to one Fe(3), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), and two equivalent Fe(4) atoms. In the second C site, C(2) is bonded in a 7-coordinate geometry to one Fe(3), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), and two equivalent Fe(5) atoms.
Fe5SiC crystallizes in the orthorhombic Cmc2_1 space group. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted water-like geometry to one Fe(6), two equivalent Si(1), one C(1), and one C(2) atom. The Fe(1)-Fe(6) bond length is 2.53 Å. There is one shorter (2.28 Å) and one longer (2.45 Å) Fe(1)-Si(1) bond length. The Fe(1)-C(1) bond length is 1.98 Å. The Fe(1)-C(2) bond length is 1.98 Å. In the second Fe site, Fe(2) is bonded in a distorted water-like geometry to two equivalent Si(1), one C(1), and one C(2) atom. Both Fe(2)-Si(1) bond lengths are 2.32 Å. The Fe(2)-C(1) bond length is 1.97 Å. The Fe(2)-C(2) bond length is 1.98 Å. In the third Fe site, Fe(3) is bonded in a distorted linear geometry to two equivalent Si(1), one C(1), and one C(2) atom. Both Fe(3)-Si(1) bond lengths are 2.58 Å. The Fe(3)-C(1) bond length is 2.14 Å. The Fe(3)-C(2) bond length is 2.17 Å. In the fourth Fe site, Fe(4) is bonded in a single-bond geometry to one Fe(6), three equivalent Si(1), and one C(1) atom. The Fe(4)-Fe(6) bond length is 2.52 Å. There are a spread of Fe(4)-Si(1) bond distances ranging from 2.54-2.73 Å. The Fe(4)-C(1) bond length is 2.02 Å. In the fifth Fe site, Fe(5) is bonded in a single-bond geometry to one Fe(6), three equivalent Si(1), and one C(2) atom. The Fe(5)-Fe(6) bond length is 2.57 Å. There are a spread of Fe(5)-Si(1) bond distances ranging from 2.53-2.75 Å. The Fe(5)-C(2) bond length is 2.01 Å. In the sixth Fe site, Fe(6) is bonded in a 10-coordinate geometry to two equivalent Fe(1), two equivalent Fe(4), two equivalent Fe(5), two equivalent Si(1), one C(1), and one C(2) atom. Both Fe(6)-Si(1) bond lengths are 2.48 Å. The Fe(6)-C(1) bond length is 2.76 Å. The Fe(6)-C(2) bond length is 2.64 Å. Si(1) is bonded to one Fe(3), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), three equivalent Fe(4), and three equivalent Fe(5) atoms to form a mixture of distorted corner, face, and edge-sharing SiFe12 cuboctahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 7-coordinate geometry to one Fe(3), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), and two equivalent Fe(4) atoms. In the second C site, C(2) is bonded in a 7-coordinate geometry to one Fe(3), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), and two equivalent Fe(5) atoms.