Mn5Fe5(SiC)2 crystallizes in the orthorhombic Cmc2_1 space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted single-bond geometry to three equivalent Si(1) and one C(1) atom. In the second Mn site, Mn(2) is bonded in a distorted single-bond geometry to three equivalent Si(1) and one C(2) atom. In the third Mn site, Mn(3) is bonded in a 5-coordinate geometry to two equivalent Fe(1), two equivalent Si(1), and one C(1) atom. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted water-like geometry to one Mn(3), 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 2-coordinate geometry to two equivalent Si(1), one C(1), and one C(2) atom. Si(1) is bonded to one Mn(3), three equivalent Mn(1), three equivalent Mn(2), one Fe(3), two equivalent Fe(1), and two equivalent Fe(2) atoms to form a mixture of corner, face, and edge-sharing SiMn7Fe5 cuboctahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 8-coordinate geometry to one Mn(3), two equivalent Mn(1), one Fe(3), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the second C site, C(2) is bonded in a 7-coordinate geometry to two equivalent Mn(2), one Fe(3), two equivalent Fe(1), and two equivalent Fe(2) atoms.
Mn5Fe5(SiC)2 crystallizes in the orthorhombic Cmc2_1 space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted single-bond geometry to three equivalent Si(1) and one C(1) atom. There are a spread of Mn(1)-Si(1) bond distances ranging from 2.52-2.71 Å. The Mn(1)-C(1) bond length is 1.99 Å. In the second Mn site, Mn(2) is bonded in a distorted single-bond geometry to three equivalent Si(1) and one C(2) atom. There are a spread of Mn(2)-Si(1) bond distances ranging from 2.56-2.66 Å. The Mn(2)-C(2) bond length is 2.01 Å. In the third Mn site, Mn(3) is bonded in a 5-coordinate geometry to two equivalent Fe(1), two equivalent Si(1), and one C(1) atom. Both Mn(3)-Fe(1) bond lengths are 2.49 Å. Both Mn(3)-Si(1) bond lengths are 2.49 Å. The Mn(3)-C(1) bond length is 2.42 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted water-like geometry to one Mn(3), two equivalent Si(1), one C(1), and one C(2) atom. There is one shorter (2.26 Å) and one longer (2.43 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. There is one shorter (2.33 Å) and one longer (2.34 Å) Fe(2)-Si(1) bond length. The Fe(2)-C(1) bond length is 2.01 Å. The Fe(2)-C(2) bond length is 1.98 Å. In the third Fe site, Fe(3) is bonded in a 2-coordinate 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 2.22 Å. The Fe(3)-C(2) bond length is 2.14 Å. Si(1) is bonded to one Mn(3), three equivalent Mn(1), three equivalent Mn(2), one Fe(3), two equivalent Fe(1), and two equivalent Fe(2) atoms to form a mixture of corner, face, and edge-sharing SiMn7Fe5 cuboctahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 8-coordinate geometry to one Mn(3), two equivalent Mn(1), one Fe(3), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the second C site, C(2) is bonded in a 7-coordinate geometry to two equivalent Mn(2), one Fe(3), two equivalent Fe(1), and two equivalent Fe(2) atoms.