DOE OSTI2020
Mg6NiSn crystallizes in the tetragonal P4_2cm space group. The structure is three-dimensional. there are five inequivalent Mg sites. In the first Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Ni and one Sn atom. There are one shorter (2.66 Å) and one longer (2.70 Å) Mg–Ni bond lengths. The Mg–Sn bond length is 3.11 Å. In the second Mg site, Mg is bonded in a 3-coordinate geometry to one Ni and two equivalent Sn atoms. The Mg–Ni bond length is 2.75 Å. There are one shorter (2.97 Å) and one longer (3.07 Å) Mg–Sn bond lengths. In the third Mg site, Mg is bonded in a distorted linear geometry to two equivalent Ni atoms. Both Mg–Ni bond lengths are 2.70 Å. In the fourth Mg site, Mg is bonded to four equivalent Sn atoms to form edge-sharing MgSn4 tetrahedra. There are two shorter (2.94 Å) and two longer (3.00 Å) Mg–Sn bond lengths. In the fifth Mg site, Mg is bonded in a distorted linear geometry to one Ni and one Sn atom. The Mg–Ni bond length is 2.55 Å. The Mg–Sn bond length is 2.90 Å. Ni is bonded in a 9-coordinate geometry to eight Mg and one Sn atom. The Ni–Sn bond length is 2.68 Å. Sn is bonded in a 10-coordinate geometry to nine Mg and one Ni atom.