MgTa3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Mg(1) is bonded to twelve equivalent Ta(1) atoms to form MgTa12 cuboctahedra that share corners with six equivalent Mg(1)Ta12 cuboctahedra, corners with twelve equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with eighteen equivalent Ta(1)Mg4Ta8 cuboctahedra, faces with eight equivalent Mg(1)Ta12 cuboctahedra, and faces with twelve equivalent Ta(1)Mg4Ta8 cuboctahedra. Ta(1) is bonded to four equivalent Mg(1) and eight equivalent Ta(1) atoms to form TaMg4Ta8 cuboctahedra that share corners with four equivalent Mg(1)Ta12 cuboctahedra, corners with fourteen equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with six equivalent Mg(1)Ta12 cuboctahedra, edges with twelve equivalent Ta(1)Mg4Ta8 cuboctahedra, faces with four equivalent Mg(1)Ta12 cuboctahedra, and faces with sixteen equivalent Ta(1)Mg4Ta8 cuboctahedra.
MgTa3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Mg(1) is bonded to twelve equivalent Ta(1) atoms to form MgTa12 cuboctahedra that share corners with six equivalent Mg(1)Ta12 cuboctahedra, corners with twelve equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with eighteen equivalent Ta(1)Mg4Ta8 cuboctahedra, faces with eight equivalent Mg(1)Ta12 cuboctahedra, and faces with twelve equivalent Ta(1)Mg4Ta8 cuboctahedra. There are six shorter (2.98 Å) and six longer (2.99 Å) Mg(1)-Ta(1) bond lengths. Ta(1) is bonded to four equivalent Mg(1) and eight equivalent Ta(1) atoms to form TaMg4Ta8 cuboctahedra that share corners with four equivalent Mg(1)Ta12 cuboctahedra, corners with fourteen equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with six equivalent Mg(1)Ta12 cuboctahedra, edges with twelve equivalent Ta(1)Mg4Ta8 cuboctahedra, faces with four equivalent Mg(1)Ta12 cuboctahedra, and faces with sixteen equivalent Ta(1)Mg4Ta8 cuboctahedra. There are a spread of Ta(1)-Ta(1) bond distances ranging from 2.90-3.05 Å.