MgTh3 is Copper-derived structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Th(1) and eight equivalent Th(2) atoms to form MgTh12 cuboctahedra that share corners with four equivalent Mg(1)Th12 cuboctahedra, corners with eight equivalent Th(1)Th8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Th12 cuboctahedra, edges with sixteen equivalent Th(2)Th8Mg4 cuboctahedra, faces with four equivalent Mg(1)Th12 cuboctahedra, faces with six equivalent Th(1)Th8Mg4 cuboctahedra, and faces with eight equivalent Th(2)Th8Mg4 cuboctahedra. There are two inequivalent Th sites. In the first Th site, Th(1) is bonded to four equivalent Mg(1) and eight equivalent Th(2) atoms to form ThTh8Mg4 cuboctahedra that share corners with four equivalent Th(1)Th8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Th12 cuboctahedra, edges with eight equivalent Th(1)Th8Mg4 cuboctahedra, edges with sixteen equivalent Th(2)Th8Mg4 cuboctahedra, faces with four equivalent Th(1)Th8Mg4 cuboctahedra, faces with six equivalent Mg(1)Th12 cuboctahedra, and faces with eight equivalent Th(2)Th8Mg4 cuboctahedra. In the second Th site, Th(2) is bonded to four equivalent Mg(1), four equivalent Th(1), and four equivalent Th(2) atoms to form ThTh8Mg4 cuboctahedra that share corners with twelve equivalent Th(2)Th8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Th12 cuboctahedra, edges with eight equivalent Th(1)Th8Mg4 cuboctahedra, edges with eight equivalent Th(2)Th8Mg4 cuboctahedra, faces with four equivalent Mg(1)Th12 cuboctahedra, faces with four equivalent Th(1)Th8Mg4 cuboctahedra, and faces with ten equivalent Th(2)Th8Mg4 cuboctahedra.
MgTh3 is Copper-derived structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Th(1) and eight equivalent Th(2) atoms to form MgTh12 cuboctahedra that share corners with four equivalent Mg(1)Th12 cuboctahedra, corners with eight equivalent Th(1)Th8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Th12 cuboctahedra, edges with sixteen equivalent Th(2)Th8Mg4 cuboctahedra, faces with four equivalent Mg(1)Th12 cuboctahedra, faces with six equivalent Th(1)Th8Mg4 cuboctahedra, and faces with eight equivalent Th(2)Th8Mg4 cuboctahedra. All Mg(1)-Th(1) bond lengths are 3.48 Å. All Mg(1)-Th(2) bond lengths are 3.53 Å. There are two inequivalent Th sites. In the first Th site, Th(1) is bonded to four equivalent Mg(1) and eight equivalent Th(2) atoms to form ThTh8Mg4 cuboctahedra that share corners with four equivalent Th(1)Th8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Th12 cuboctahedra, edges with eight equivalent Th(1)Th8Mg4 cuboctahedra, edges with sixteen equivalent Th(2)Th8Mg4 cuboctahedra, faces with four equivalent Th(1)Th8Mg4 cuboctahedra, faces with six equivalent Mg(1)Th12 cuboctahedra, and faces with eight equivalent Th(2)Th8Mg4 cuboctahedra. All Th(1)-Th(2) bond lengths are 3.53 Å. In the second Th site, Th(2) is bonded to four equivalent Mg(1), four equivalent Th(1), and four equivalent Th(2) atoms to form ThTh8Mg4 cuboctahedra that share corners with twelve equivalent Th(2)Th8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Th12 cuboctahedra, edges with eight equivalent Th(1)Th8Mg4 cuboctahedra, edges with eight equivalent Th(2)Th8Mg4 cuboctahedra, faces with four equivalent Mg(1)Th12 cuboctahedra, faces with four equivalent Th(1)Th8Mg4 cuboctahedra, and faces with ten equivalent Th(2)Th8Mg4 cuboctahedra. All Th(2)-Th(2) bond lengths are 3.48 Å.