MgPr3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Pr(1) and eight equivalent Pr(2) atoms to form MgPr12 cuboctahedra that share corners with four equivalent Mg(1)Pr12 cuboctahedra, corners with eight equivalent Pr(1)Pr8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Pr12 cuboctahedra, edges with sixteen equivalent Pr(2)Pr8Mg4 cuboctahedra, faces with four equivalent Mg(1)Pr12 cuboctahedra, faces with six equivalent Pr(1)Pr8Mg4 cuboctahedra, and faces with eight equivalent Pr(2)Pr8Mg4 cuboctahedra. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to four equivalent Mg(1) and eight equivalent Pr(2) atoms to form PrPr8Mg4 cuboctahedra that share corners with four equivalent Pr(1)Pr8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Pr12 cuboctahedra, edges with eight equivalent Pr(1)Pr8Mg4 cuboctahedra, edges with sixteen equivalent Pr(2)Pr8Mg4 cuboctahedra, faces with four equivalent Pr(1)Pr8Mg4 cuboctahedra, faces with six equivalent Mg(1)Pr12 cuboctahedra, and faces with eight equivalent Pr(2)Pr8Mg4 cuboctahedra. In the second Pr site, Pr(2) is bonded to four equivalent Mg(1), four equivalent Pr(1), and four equivalent Pr(2) atoms to form PrPr8Mg4 cuboctahedra that share corners with twelve equivalent Pr(2)Pr8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Pr12 cuboctahedra, edges with eight equivalent Pr(1)Pr8Mg4 cuboctahedra, edges with eight equivalent Pr(2)Pr8Mg4 cuboctahedra, faces with four equivalent Mg(1)Pr12 cuboctahedra, faces with four equivalent Pr(1)Pr8Mg4 cuboctahedra, and faces with ten equivalent Pr(2)Pr8Mg4 cuboctahedra.
MgPr3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Pr(1) and eight equivalent Pr(2) atoms to form MgPr12 cuboctahedra that share corners with four equivalent Mg(1)Pr12 cuboctahedra, corners with eight equivalent Pr(1)Pr8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Pr12 cuboctahedra, edges with sixteen equivalent Pr(2)Pr8Mg4 cuboctahedra, faces with four equivalent Mg(1)Pr12 cuboctahedra, faces with six equivalent Pr(1)Pr8Mg4 cuboctahedra, and faces with eight equivalent Pr(2)Pr8Mg4 cuboctahedra. All Mg(1)-Pr(1) bond lengths are 3.56 Å. All Mg(1)-Pr(2) bond lengths are 3.60 Å. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to four equivalent Mg(1) and eight equivalent Pr(2) atoms to form PrPr8Mg4 cuboctahedra that share corners with four equivalent Pr(1)Pr8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Pr12 cuboctahedra, edges with eight equivalent Pr(1)Pr8Mg4 cuboctahedra, edges with sixteen equivalent Pr(2)Pr8Mg4 cuboctahedra, faces with four equivalent Pr(1)Pr8Mg4 cuboctahedra, faces with six equivalent Mg(1)Pr12 cuboctahedra, and faces with eight equivalent Pr(2)Pr8Mg4 cuboctahedra. All Pr(1)-Pr(2) bond lengths are 3.60 Å. In the second Pr site, Pr(2) is bonded to four equivalent Mg(1), four equivalent Pr(1), and four equivalent Pr(2) atoms to form PrPr8Mg4 cuboctahedra that share corners with twelve equivalent Pr(2)Pr8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Pr12 cuboctahedra, edges with eight equivalent Pr(1)Pr8Mg4 cuboctahedra, edges with eight equivalent Pr(2)Pr8Mg4 cuboctahedra, faces with four equivalent Mg(1)Pr12 cuboctahedra, faces with four equivalent Pr(1)Pr8Mg4 cuboctahedra, and faces with ten equivalent Pr(2)Pr8Mg4 cuboctahedra. All Pr(2)-Pr(2) bond lengths are 3.56 Å.