Materials Data on Sm3Mg by Materials Project
MgSm3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Mg is bonded to twelve Sm atoms to form MgSm12 cuboctahedra that share corners with four equivalent MgSm12 cuboctahedra, corners with eight equivalent SmSm8Mg4 cuboctahedra, edges with eight equivalent MgSm12 cuboctahedra, edges with sixteen equivalent SmSm8Mg4 cuboctahedra, faces with four equivalent MgSm12 cuboctahedra, and faces with fourteen SmSm8Mg4 cuboctahedra. There are four shorter (3.51 Å) and eight longer (3.53 Å) Mg–Sm bond lengths. There are two inequivalent Sm sites. In the first Sm site, Sm is bonded to four equivalent Mg and eight equivalent Sm atoms to form SmSm8Mg4 cuboctahedra that share corners with four equivalent SmSm8Mg4 cuboctahedra, corners with eight equivalent MgSm12 cuboctahedra, edges with twenty-four SmSm8Mg4 cuboctahedra, faces with six equivalent MgSm12 cuboctahedra, and faces with twelve SmSm8Mg4 cuboctahedra. All Sm–Sm bond lengths are 3.53 Å. In the second Sm site, Sm is bonded to four equivalent Mg and eight Sm atoms to form SmSm8Mg4 cuboctahedra that share corners with twelve equivalent SmSm8Mg4 cuboctahedra, edges with eight equivalent MgSm12 cuboctahedra, edges with sixteen SmSm8Mg4 cuboctahedra, faces with four equivalent MgSm12 cuboctahedra, and faces with fourteen SmSm8Mg4 cuboctahedra. All Sm–Sm bond lengths are 3.51 Å.