Materials Data on MgTa3 by Materials Project
MgTa3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Mg is bonded to twelve Ta atoms to form MgTa12 cuboctahedra that share corners with six equivalent MgTa12 cuboctahedra, corners with twelve TaMg4Ta8 cuboctahedra, edges with eighteen TaMg4Ta8 cuboctahedra, faces with eight equivalent MgTa12 cuboctahedra, and faces with twelve TaMg4Ta8 cuboctahedra. There are six shorter (2.98 Å) and six longer (2.99 Å) Mg–Ta bond lengths. There are two inequivalent Ta sites. In the first Ta site, Ta is bonded to four equivalent Mg and eight Ta atoms to form TaMg4Ta8 cuboctahedra that share corners with four equivalent MgTa12 cuboctahedra, corners with fourteen TaMg4Ta8 cuboctahedra, edges with six equivalent MgTa12 cuboctahedra, edges with twelve TaMg4Ta8 cuboctahedra, faces with four equivalent MgTa12 cuboctahedra, and faces with sixteen TaMg4Ta8 cuboctahedra. There are a spread of Ta–Ta bond distances ranging from 2.90–3.05 Å. In the second Ta site, Ta is bonded to four equivalent Mg and eight equivalent Ta atoms to form TaMg4Ta8 cuboctahedra that share corners with four equivalent MgTa12 cuboctahedra, corners with fourteen TaMg4Ta8 cuboctahedra, edges with six equivalent MgTa12 cuboctahedra, edges with twelve equivalent TaMg4Ta8 cuboctahedra, faces with four equivalent MgTa12 cuboctahedra, and faces with sixteen TaMg4Ta8 cuboctahedra.