Mg2Sc is Magnesium-derived structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent Mg(2), four equivalent Mg(1), and five equivalent Sc(1) atoms to form MgMg7Sc5 cuboctahedra that share corners with six equivalent Mg(1)Mg7Sc5 cuboctahedra, corners with six equivalent Mg(2)Mg8Sc4 cuboctahedra, corners with six equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with five equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with six equivalent Mg(1)Mg7Sc5 cuboctahedra, edges with seven equivalent Mg(2)Mg8Sc4 cuboctahedra, faces with five equivalent Mg(1)Mg7Sc5 cuboctahedra, faces with seven equivalent Mg(2)Mg8Sc4 cuboctahedra, and faces with eight equivalent Sc(1)Mg9Sc3 cuboctahedra. In the second Mg site, Mg(2) is bonded to three equivalent Mg(1), five equivalent Mg(2), and four equivalent Sc(1) atoms to form MgMg8Sc4 cuboctahedra that share corners with six equivalent Mg(1)Mg7Sc5 cuboctahedra, corners with six equivalent Mg(2)Mg8Sc4 cuboctahedra, corners with six equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with two equivalent Mg(2)Mg8Sc4 cuboctahedra, edges with seven equivalent Mg(1)Mg7Sc5 cuboctahedra, edges with nine equivalent Sc(1)Mg9Sc3 cuboctahedra, faces with six equivalent Sc(1)Mg9Sc3 cuboctahedra, faces with seven equivalent Mg(1)Mg7Sc5 cuboctahedra, and faces with seven equivalent Mg(2)Mg8Sc4 cuboctahedra. Sc(1) is bonded to four equivalent Mg(2), five equivalent Mg(1), and three equivalent Sc(1) atoms to form ScMg9Sc3 cuboctahedra that share corners with six equivalent Mg(1)Mg7Sc5 cuboctahedra, corners with six equivalent Mg(2)Mg8Sc4 cuboctahedra, corners with six equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with four equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with five equivalent Mg(1)Mg7Sc5 cuboctahedra, edges with nine equivalent Mg(2)Mg8Sc4 cuboctahedra, faces with six equivalent Mg(2)Mg8Sc4 cuboctahedra, faces with six equivalent Sc(1)Mg9Sc3 cuboctahedra, and faces with eight equivalent Mg(1)Mg7Sc5 cuboctahedra.
Mg2Sc is Magnesium-derived structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent Mg(2), four equivalent Mg(1), and five equivalent Sc(1) atoms to form MgMg7Sc5 cuboctahedra that share corners with six equivalent Mg(1)Mg7Sc5 cuboctahedra, corners with six equivalent Mg(2)Mg8Sc4 cuboctahedra, corners with six equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with five equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with six equivalent Mg(1)Mg7Sc5 cuboctahedra, edges with seven equivalent Mg(2)Mg8Sc4 cuboctahedra, faces with five equivalent Mg(1)Mg7Sc5 cuboctahedra, faces with seven equivalent Mg(2)Mg8Sc4 cuboctahedra, and faces with eight equivalent Sc(1)Mg9Sc3 cuboctahedra. There are two shorter (3.14 Å) and one longer (3.21 Å) Mg(1)-Mg(2) bond length. There are two shorter (3.17 Å) and two longer (3.19 Å) Mg(1)-Mg(1) bond lengths. There are two shorter (3.21 Å) and three longer (3.26 Å) Mg(1)-Sc(1) bond lengths. In the second Mg site, Mg(2) is bonded to three equivalent Mg(1), five equivalent Mg(2), and four equivalent Sc(1) atoms to form MgMg8Sc4 cuboctahedra that share corners with six equivalent Mg(1)Mg7Sc5 cuboctahedra, corners with six equivalent Mg(2)Mg8Sc4 cuboctahedra, corners with six equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with two equivalent Mg(2)Mg8Sc4 cuboctahedra, edges with seven equivalent Mg(1)Mg7Sc5 cuboctahedra, edges with nine equivalent Sc(1)Mg9Sc3 cuboctahedra, faces with six equivalent Sc(1)Mg9Sc3 cuboctahedra, faces with seven equivalent Mg(1)Mg7Sc5 cuboctahedra, and faces with seven equivalent Mg(2)Mg8Sc4 cuboctahedra. There are a spread of Mg(2)-Mg(2) bond distances ranging from 3.17-3.32 Å. There are two shorter (3.21 Å) and two longer (3.22 Å) Mg(2)-Sc(1) bond lengths. Sc(1) is bonded to four equivalent Mg(2), five equivalent Mg(1), and three equivalent Sc(1) atoms to form ScMg9Sc3 cuboctahedra that share corners with six equivalent Mg(1)Mg7Sc5 cuboctahedra, corners with six equivalent Mg(2)Mg8Sc4 cuboctahedra, corners with six equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with four equivalent Sc(1)Mg9Sc3 cuboctahedra, edges with five equivalent Mg(1)Mg7Sc5 cuboctahedra, edges with nine equivalent Mg(2)Mg8Sc4 cuboctahedra, faces with six equivalent Mg(2)Mg8Sc4 cuboctahedra, faces with six equivalent Sc(1)Mg9Sc3 cuboctahedra, and faces with eight equivalent Mg(1)Mg7Sc5 cuboctahedra. There are two shorter (3.17 Å) and one longer (3.19 Å) Sc(1)-Sc(1) bond length.