Sc3OsC4 crystallizes in the orthorhombic Immm space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to four equivalent Os(1) and eight equivalent C(1) atoms to form distorted ScOs4C8 cuboctahedra that share corners with four equivalent Sc(1)Os4C8 cuboctahedra, corners with eight equivalent C(1)Sc5OsC pentagonal bipyramids, edges with two equivalent Sc(1)Os4C8 cuboctahedra, edges with eight equivalent C(1)Sc5OsC pentagonal bipyramids, and faces with two equivalent Sc(1)Os4C8 cuboctahedra. In the second Sc site, Sc(2) is bonded in a 6-coordinate geometry to six equivalent C(1) atoms. Os(1) is bonded in a distorted square co-planar geometry to four equivalent Sc(1) and four equivalent C(1) atoms. C(1) is bonded to two equivalent Sc(1), three equivalent Sc(2), one Os(1), and one C(1) atom to form distorted CSc5OsC pentagonal bipyramids that share corners with two equivalent Sc(1)Os4C8 cuboctahedra, corners with thirteen equivalent C(1)Sc5OsC pentagonal bipyramids, edges with two equivalent Sc(1)Os4C8 cuboctahedra, edges with five equivalent C(1)Sc5OsC pentagonal bipyramids, and faces with three equivalent C(1)Sc5OsC pentagonal bipyramids.
Sc3OsC4 crystallizes in the orthorhombic Immm space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to four equivalent Os(1) and eight equivalent C(1) atoms to form distorted ScOs4C8 cuboctahedra that share corners with four equivalent Sc(1)Os4C8 cuboctahedra, corners with eight equivalent C(1)Sc5OsC pentagonal bipyramids, edges with two equivalent Sc(1)Os4C8 cuboctahedra, edges with eight equivalent C(1)Sc5OsC pentagonal bipyramids, and faces with two equivalent Sc(1)Os4C8 cuboctahedra. All Sc(1)-Os(1) bond lengths are 2.80 Å. All Sc(1)-C(1) bond lengths are 2.42 Å. In the second Sc site, Sc(2) is bonded in a 6-coordinate geometry to six equivalent C(1) atoms. There are two shorter (2.35 Å) and four longer (2.39 Å) Sc(2)-C(1) bond lengths. Os(1) is bonded in a distorted square co-planar geometry to four equivalent Sc(1) and four equivalent C(1) atoms. All Os(1)-C(1) bond lengths are 2.20 Å. C(1) is bonded to two equivalent Sc(1), three equivalent Sc(2), one Os(1), and one C(1) atom to form distorted CSc5OsC pentagonal bipyramids that share corners with two equivalent Sc(1)Os4C8 cuboctahedra, corners with thirteen equivalent C(1)Sc5OsC pentagonal bipyramids, edges with two equivalent Sc(1)Os4C8 cuboctahedra, edges with five equivalent C(1)Sc5OsC pentagonal bipyramids, and faces with three equivalent C(1)Sc5OsC pentagonal bipyramids. The C(1)-C(1) bond length is 1.44 Å.