DOE OSTI2020
EuNi9Ge4 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. Eu is bonded in a 8-coordinate geometry to sixteen Ni and eight equivalent Ge atoms. There are eight shorter (3.43 Å) and eight longer (3.48 Å) Eu–Ni bond lengths. All Eu–Ge bond lengths are 3.40 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded in a 12-coordinate geometry to two equivalent Eu, six Ni, and four equivalent Ge atoms. There are a spread of Ni–Ni bond distances ranging from 2.43–2.66 Å. There are two shorter (2.55 Å) and two longer (2.59 Å) Ni–Ge bond lengths. In the second Ni site, Ni is bonded in a cuboctahedral geometry to eight Ni and four equivalent Ge atoms. All Ni–Ni bond lengths are 2.45 Å. All Ni–Ge bond lengths are 2.43 Å. In the third Ni site, Ni is bonded in a 12-coordinate geometry to two equivalent Eu, eight Ni, and two equivalent Ge atoms. There are two shorter (2.49 Å) and one longer (2.72 Å) Ni–Ni bond lengths. Both Ni–Ge bond lengths are 2.52 Å. Ge is bonded in a 12-coordinate geometry to two equivalent Eu, seven Ni, and three equivalent Ge atoms. There are two shorter (2.68 Å) and one longer (2.70 Å) Ge–Ge bond lengths.