Sc5Sb3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to one Sb(1) and four equivalent Sb(2) atoms to form distorted edge-sharing ScSb5 square pyramids. In the second Sc site, Sc(2) is bonded in a 5-coordinate geometry to one Sb(1) and four equivalent Sb(2) atoms. In the third Sc site, Sc(3) is bonded in a 6-coordinate geometry to two equivalent Sb(1) and four equivalent Sb(2) atoms. In the fourth Sc site, Sc(4) is bonded in a 5-coordinate geometry to two equivalent Sb(1) and three equivalent Sb(2) atoms. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 8-coordinate geometry to one Sc(1), one Sc(2), two equivalent Sc(3), and four equivalent Sc(4) atoms. In the second Sb site, Sb(2) is bonded in a 9-coordinate geometry to two equivalent Sc(1), two equivalent Sc(2), two equivalent Sc(3), and three equivalent Sc(4) atoms.
Sc5Sb3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to one Sb(1) and four equivalent Sb(2) atoms to form distorted edge-sharing ScSb5 square pyramids. The Sc(1)-Sb(1) bond length is 2.97 Å. There are two shorter (2.96 Å) and two longer (2.99 Å) Sc(1)-Sb(2) bond lengths. In the second Sc site, Sc(2) is bonded in a 5-coordinate geometry to one Sb(1) and four equivalent Sb(2) atoms. The Sc(2)-Sb(1) bond length is 2.88 Å. There are two shorter (2.97 Å) and two longer (3.11 Å) Sc(2)-Sb(2) bond lengths. In the third Sc site, Sc(3) is bonded in a 6-coordinate geometry to two equivalent Sb(1) and four equivalent Sb(2) atoms. There is one shorter (2.91 Å) and one longer (3.20 Å) Sc(3)-Sb(1) bond length. There are two shorter (2.97 Å) and two longer (3.17 Å) Sc(3)-Sb(2) bond lengths. In the fourth Sc site, Sc(4) is bonded in a 5-coordinate geometry to two equivalent Sb(1) and three equivalent Sb(2) atoms. There is one shorter (2.88 Å) and one longer (2.93 Å) Sc(4)-Sb(1) bond length. There are a spread of Sc(4)-Sb(2) bond distances ranging from 3.11-3.23 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 8-coordinate geometry to one Sc(1), one Sc(2), two equivalent Sc(3), and four equivalent Sc(4) atoms. In the second Sb site, Sb(2) is bonded in a 9-coordinate geometry to two equivalent Sc(1), two equivalent Sc(2), two equivalent Sc(3), and three equivalent Sc(4) atoms.