Materials Data on Pm3Mg by Materials Project
MgPm3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Mg is bonded to twelve Pm atoms to form MgPm12 cuboctahedra that share corners with four equivalent MgPm12 cuboctahedra, corners with eight equivalent PmPm8Mg4 cuboctahedra, edges with eight equivalent MgPm12 cuboctahedra, edges with sixteen equivalent PmPm8Mg4 cuboctahedra, faces with four equivalent MgPm12 cuboctahedra, and faces with fourteen PmPm8Mg4 cuboctahedra. All Mg–Pm bond lengths are 3.54 Å. There are two inequivalent Pm sites. In the first Pm site, Pm is bonded to four equivalent Mg and eight equivalent Pm atoms to form PmPm8Mg4 cuboctahedra that share corners with four equivalent PmPm8Mg4 cuboctahedra, corners with eight equivalent MgPm12 cuboctahedra, edges with twenty-four PmPm8Mg4 cuboctahedra, faces with six equivalent MgPm12 cuboctahedra, and faces with twelve PmPm8Mg4 cuboctahedra. All Pm–Pm bond lengths are 3.54 Å. In the second Pm site, Pm is bonded to four equivalent Mg and eight Pm atoms to form PmPm8Mg4 cuboctahedra that share corners with twelve equivalent PmPm8Mg4 cuboctahedra, edges with eight equivalent MgPm12 cuboctahedra, edges with sixteen PmPm8Mg4 cuboctahedra, faces with four equivalent MgPm12 cuboctahedra, and faces with fourteen PmPm8Mg4 cuboctahedra. All Pm–Pm bond lengths are 3.54 Å.