Materials Data on MgNi3 by Materials Project
MgNi3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Mg is bonded to twelve Ni atoms to form MgNi12 cuboctahedra that share corners with four equivalent MgNi12 cuboctahedra, corners with eight equivalent NiMg4Ni8 cuboctahedra, edges with eight equivalent MgNi12 cuboctahedra, edges with sixteen equivalent NiMg4Ni8 cuboctahedra, faces with four equivalent MgNi12 cuboctahedra, and faces with fourteen NiMg4Ni8 cuboctahedra. There are eight shorter (2.57 Å) and four longer (2.59 Å) Mg–Ni bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to four equivalent Mg and eight equivalent Ni atoms to form distorted NiMg4Ni8 cuboctahedra that share corners with four equivalent NiMg4Ni8 cuboctahedra, corners with eight equivalent MgNi12 cuboctahedra, edges with twenty-four NiMg4Ni8 cuboctahedra, faces with six equivalent MgNi12 cuboctahedra, and faces with twelve NiMg4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.57 Å. In the second Ni site, Ni is bonded to four equivalent Mg and eight Ni atoms to form distorted NiMg4Ni8 cuboctahedra that share corners with twelve equivalent NiMg4Ni8 cuboctahedra, edges with eight equivalent MgNi12 cuboctahedra, edges with sixteen NiMg4Ni8 cuboctahedra, faces with four equivalent MgNi12 cuboctahedra, and faces with fourteen NiMg4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.59 Å.