MgNi3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Mg(1) is bonded to twelve Ni(1,1) atoms to form MgNi12 cuboctahedra that share corners with six equivalent Mg(1)Ni12 cuboctahedra; corners with twelve equivalent Ni(1)Mg4Ni8 cuboctahedra; edges with eighteen Ni(1,1)Mg4Ni8 cuboctahedra; faces with eight equivalent Mg(1)Ni12 cuboctahedra; and faces with twelve Ni(1,1)Mg4Ni8 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Mg(1) and eight equivalent Ni(1) atoms to form distorted NiMg4Ni8 cuboctahedra that share corners with four equivalent Mg(1)Ni12 cuboctahedra; corners with fourteen equivalent Ni(1)Mg4Ni8 cuboctahedra; edges with six equivalent Mg(1)Ni12 cuboctahedra; edges with twelve equivalent Ni(1)Mg4Ni8 cuboctahedra; faces with four equivalent Mg(1)Ni12 cuboctahedra; and faces with sixteen Ni(1,1)Mg4Ni8 cuboctahedra. In the second Ni site, Ni(1) is bonded to four equivalent Mg(1) and eight equivalent Ni(1) atoms to form distorted NiMg4Ni8 cuboctahedra that share corners with four equivalent Mg(1)Ni12 cuboctahedra; corners with fourteen Ni(1,1)Mg4Ni8 cuboctahedra; edges with six equivalent Mg(1)Ni12 cuboctahedra; edges with twelve equivalent Ni(1)Mg4Ni8 cuboctahedra; faces with four equivalent Mg(1)Ni12 cuboctahedra; and faces with sixteen Ni(1,1)Mg4Ni8 cuboctahedra.
MgNi3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Mg(1) is bonded to twelve Ni(1,1) atoms to form MgNi12 cuboctahedra that share corners with six equivalent Mg(1)Ni12 cuboctahedra; corners with twelve equivalent Ni(1)Mg4Ni8 cuboctahedra; edges with eighteen Ni(1,1)Mg4Ni8 cuboctahedra; faces with eight equivalent Mg(1)Ni12 cuboctahedra; and faces with twelve Ni(1,1)Mg4Ni8 cuboctahedra. All Mg(1)-Ni(1,1) bond lengths are 2.60 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Mg(1) and eight equivalent Ni(1) atoms to form distorted NiMg4Ni8 cuboctahedra that share corners with four equivalent Mg(1)Ni12 cuboctahedra; corners with fourteen equivalent Ni(1)Mg4Ni8 cuboctahedra; edges with six equivalent Mg(1)Ni12 cuboctahedra; edges with twelve equivalent Ni(1)Mg4Ni8 cuboctahedra; faces with four equivalent Mg(1)Ni12 cuboctahedra; and faces with sixteen Ni(1,1)Mg4Ni8 cuboctahedra. There are a spread of Ni(1)-Ni(1) bond distances ranging from 2.49-2.71 Å. In the second Ni site, Ni(1) is bonded to four equivalent Mg(1) and eight equivalent Ni(1) atoms to form distorted NiMg4Ni8 cuboctahedra that share corners with four equivalent Mg(1)Ni12 cuboctahedra; corners with fourteen Ni(1,1)Mg4Ni8 cuboctahedra; edges with six equivalent Mg(1)Ni12 cuboctahedra; edges with twelve equivalent Ni(1)Mg4Ni8 cuboctahedra; faces with four equivalent Mg(1)Ni12 cuboctahedra; and faces with sixteen Ni(1,1)Mg4Ni8 cuboctahedra. There are a spread of Ni(1)-Ni(1) bond distances ranging from 2.49-2.71 Å.